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The Teacher’s Aid 

OR 

SUPPLEMENTARY WORK 

FOR 

PUBLIC SCHOOLS 



ISABELLA PATTON 

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1901. 

J. S. HYLAND & CO., PUBLISHERS, 

CHICAGO. 

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THE LIBRARY OF 

congress, 

Two CuKiW Received 

NOV. 4 1901 

Copyright entry 
CUAS 9l)«' XXo. No. 

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copy a 


COPYRIGHT 1901 

BY 

ISABELLA PATTON. 


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PREFACE. 


To Public School Teachers, Pupils and Patrons. 

Having been a public school teacher for years, and during 
that time felt the lack of, and the need for, books in the line 
of supplementary work, I have compiled this little volume, 
with the hope that it may be an aid to teachers and pupils 
alike, by breaking the monotony of the daily routine. 

The work is designed for general exercise, in which 
from five to fifteen minutes could be devoted daily to the 
reading and discussion of one topic. Or several days could 
be devoted to the same topic, teachers and pupils talking 
freely of their own personal knowledge of the topic under 
discussion. 

In this manner much valuable and interesting informa¬ 
tion may be obtained of the many very common and useful 
things by which we are surrounded, and of whose origin 
we are in doubt or ignorance. 

The knowledge herein contained has been obtained from 
various sources, among which may be named Encyclo¬ 
pedias, Natural Histories, Newspapers, Magazines, Dic¬ 
tionaries, etc., from the personal knowledge of friends and 
acquaintances, and my own personal knowledge, obser¬ 
vation and experience. 

I most sincerely wish that the work may prove a benefit 
and a true aid to every teacher and pupil in whose hands 
it may be placed. During my own work in the school 
room, I would have hailed with joy the possession of a 
similar book. 

Respectfully submitting this work, and hoping it will 
find its way into the hands of every teacher, pupil and 
parent, and into every public school and home in the land, 
and meet the approval of all who read it, I am, 

Yours sincerely, 


The Author. 




SUGGESTIONS TO TEACHERS. 


In presenting this book to the public school teacher, it 
is with the hope that each topic will be enlarged upon. 

Pupils should be encouraged to procure all information 
possible, from any and all available sources. They should 
also be encouraged to ask questions, and to freely impart 
any and all knowledge which they may have acquired 
regarding the subject under discussion. 

Stimulate in them a desire to learn as much as possible, 
in regard to the origin of the many common things with 
which they are brought in daily contact, the sources of 
which are vague, or perhaps unknown. 

In many cases it will be possible to illustrate the subject 
by the use of a specimen, or specimens. And when this is 
practicable, it should be done. 

A word of judicious praise for efforts made, and for 
knowledge acquired, will invariably act as a stimulus for 
further thought and research. 

While many of the topics here presented are dealt with 
in a brief manner, they can be enlarged upon by the addi¬ 
tion of the many facts and figures presented by instructors 
and pupils, until each topic becomes a lengthy treatise, 
which will be instructive, interesting and beneficial to all. 

This work, if placed in the home, should meet with the 
same success which, I trust, it will meet with in the school 


room. 




INDEX. 


Page. 

Asbestos. 260 

Aloe. 128 

Arrow Root. 223 

Arsenic. 317 

Alum. 145 

Ashe. . .. 236 

Aluminium. 323 

Albumen. 130 

Alcohol. 109 

Alabaster. 234 

Butter. 41 

Bullets. 254 

Bamboo. 107 

Bronze. 270 

Borax. 140 

Benzoin. 308 

Brick. 44 

Bread. 13 

Broom Corn. 46 

Bristles. 228 

Brass. 267 

Brandy. 47 

Coal. 141 

Coffee. 17 

Coke. 229 

Cork. 259 

China. 192 

Candles. 121 

Camphor. 136 

Copper. 251 

Cheese. 113 

Cotton. 261 

Copperas. 250 

Charcoal. 131 

Chalk. 9 

Cinnamon. 301 

Cuttle Bone. 153 

Cream of Tartar. 275 

Candy. 195 

Celluloid. 234 

Cider. 312 

Cement. HI 

Castor Oil. 95 

Cochineal. 124 

Coral. 297 

Clay. 69 

Cocoa. 247 

Cocoa Nut. 123 

Delf .. 192 

Diamond. 66 


Page. 

DyeStuffs. 134 

Ebony. 265 

Essences. 274 

Eider-Down. 220 

Emery. 303 

Flax. 281 

Fur . 64 

Feathers. 321 

Featherbone. 294 

Flour. 36 

Gypsum. 231 

Gum Arabic. 194 

Gum Elastic. 327 

Gelatin. 176 

Gutta Percha. 179 

Grind-Stone. 239 

Glue. 49 

Glycerine. 196 

Ginger. 101 

Glass. 34 

Granite. 139 

Gold. 59 

Gluten. 178 

Gunpowder. 103 

Gum. 240 

Hay. 311 

Horn. 201 

Honey. 37 

Hour Glass. 168 

Hominy. 106 

Hide. 191 

India Rubber. 327 

Ivory. 319 

Ink. 11 

Isinglass. 43 

Indigo .. 256 

Iron. 39 

Jet-.'. 156 

Jute. 206 

Lace. 327 

Lard. 266 

Lime. 326 

Limestone. 127 

Lead. 218 

Leather. 161 

Linen. 61 

Morocco Leather. 273 

Mother of Pearl. 279 




































































































INDEX. 


Matches. 

Page. 

. 62 

Mirrors. 

. 276 

Marble. 

. 219 

Mace. 

. 213 

Mahogany . 

. 243 

Magnesium. 

. 278 

Macaroni. 

. 52 

Majolica. 

. 213 

Mica. 

. 97 

Mortar. 

. 54 

Mushroom. 

. 99 

Nitre. 

. 243 

Nutmeg. 

. 53 

Opium. 

. 88 

Oils. 

. 284 

Oyster. 

. 151 

Platinum. 

. 163 

Perfumery. 

. 71 

Putty. 

. 218 

Pewter. 

. 217 

Plumbago. 

. 91 

Pearl. 

. 55 

Peat. 

. 84 

Plaster of Paris . . 

. 232 

lottery. 

. 164 

Pens. 

. 74 

Paper. 

. 183 

Parchment. 

. 181 

Pins. 

. 27 

Pitch. 

. 241 

Potash. 

. 214 

Petroleum. 

. 93 

Pumice. 

. 79 

Poison. 

. 216 

Plaster. 

. 235 

Paint. 

. 304 

Pepper. 

. 31 

Porcelain. 

. 185 

Quinine. 

. 157 

Quills. 

. 154 

Quicklime. 

. 131 

Quicksilver. 

.. 227 

Queensware ...... 

..296 

Raisins.,... 

. 21 

Rattan ......... 

. 157 

Resin. 

.; 135 

Rope. 

. 155 


Page. 

Rice. 306 

Rushes. 295 

Sand. 20 

Sand Paper. 238 

Sponge. 209 

Sarcophagus. 292 

Silver. 225 

Stone. 244 

Silk. 117 

Soap. 169 

Starch . 314 

Salt. 166 

Straw. 23 

Sugar. 286 

Shot. 25 

Soda. 158 

Sulphur. 171 

Sorghum.187 

Tile ;. 203 

Teak. 138 

Tiles. 272 

Tin. 173 

Tallow. 189 

Tapioca. 264 

Tobacco. 148 

Tar. 82 

Turpentine. 212 

Tea. 80 

Vanilla. 152 

Varnish. 297 

Verdigris. 194 

Vermilion. 233 

Veneer. 236 

Vinegar. 197 

Vitriol. 207 

Wax.,. 299 

Wine. 22 

Willow. 180 

Whetstone. 237 

Whalebone. 242 

Whitewash. 232 

Whisky. 144 

Wool. 202 

Wire . ...... . 280 

Yeast.. „ .. 293 

Zinc...... 198 
































































































ENDORSEMENTS. 


Urbana, Ill., June 27, 1901. 

Text-book teaching is a survival of the fittest in education and is the method 
most employed in American common schools. It is supplanting in a con¬ 
siderable degree the lecture system in our best colleges and professional schools. 
But there is danger of making too much of the class text-book. One author 
can seldom be taken as authority on all subjects and one statement of a fact 
seldom means much to a beginner. The habit of looking up opinions of others 
ought largely to be encouraged and provision should be made in every school for 
ready references. The book in preparation by the Misses Paton is designed 
to meet this want in an inexpensive way, and promises to be very useful. 

T. J. Burrill, Professor of Botany, University of Illinois. 


3 


Danville, Ill., June 18, 1901. 

Having examined the proof sheets of the “Teacher’s Aid, or Supplementary 
Work for Public Schools,” by Isabella Patton, I have no hesitancy in giving 
the same my full endorsement. Eight years’ experience as County Super¬ 
intendent of Schools of Vermilion County, Illinois, together with several 
years’ experience as a teacher in the public schools, convinces me that a work 
on the lines laid down in the aforesaid work is very much needed in our public 
schools. I would recommend the book to the teachers of the schools of this 
county and to the parents of all school children. 

C. V. Guy, Ex-County Superintendent of Schools. 


3 


Champaign, Ill., June 18, 1901. 

I desire very fully to endorse all that Mr. Guy has said. 

Joseph Carter, Supt. of City Schools. 

3 

I believe that the volume entitled the “Teacher’s Aid or Supplementary 
Work for Public Schools,” will furnish material in a condensed, available 
form, that can be placed in the hands of every teacher and pupil in the country 
schools. The articles are well arranged, and treat of every-day subjects which 
are rarely treated of in detail in the text-books used. I consider it a volume 
of much value to teachers, and especially to those of the country schools. 

Respectfully, 

R. B. Holmes, Supt. Vermilion Co. Schools. 




ENDORSEMENTS. 


Danville, Ill., June 18, 1901. 

I take pleasure in saying that I have examined some of the advance sheets 
of “The Teacher’s Aid, or Supplementary Work for Public Schools,” by Isabella 
Patton, and find it treats of some two hundred topics, including those things 
with which the pupils of our schools should be familiar. It will be a great help 
to teachers and parents in giving accurate instruction on these topics. It is 
really an encyclopedia of the topics treated. With this book in hand a teacher 
can always find interesting work and accurate information for pupils. I com¬ 
mend the work to teachers, and parents with small children. 

Respectfully, 

W. R. Jewell. 


3 


Danville, Ill., June 18, 1901. 

Having examined the copy of “The Teacher’s Aid, or Supplementary 
Work for Public Schools,” I will say that I believe it will be an excellent aid 
to teachers in the schools so much needing reference books. Its presence in 
a school will incite teachers to methods of investigation. 

L. H. Griffith, Supt. Danville Public Schools. 

3 


Urbana, Ill., June 20, 1901. 

To Interested Parties: 

I have looked over a sufficient number of the advance sheets of “The 
Teacher’s Aid” to apprehend the plan of its auther. It is a home and school 
reference book treating somewhat fully of the topics enumerated in its index, 
and treats them in a sympathetic and pleasant manner. It is one of the 
numerous reference books for homes that ought to surround childhood. Only 
by placing books about children can they be induced to the reading habit, 
and this will be a good book to place in the circle. 

Most truly yours, 

J. W. Hays, Supt. City Schools. 



THE TEACHER’S AID. 


CHALK. 

Chalk is a well-known variety of limestone, a carbonate 
of lime or calcareous earth. It is considered as an earth- 
mineral. 

It occurs abundantly in great stratas in some localities, 
and claims the attention of both geologist and mineralogist. 

In its native state it is usually of a yellowish-white or 
a snow-white color. It is opaque, soft, and admits of 
being pulverized, and also of taking a good polish. It is 
easily broken, and its earthy fracture is rough to the touch. 

Chalk generally contains a little silica, alumina or mag¬ 
nesia, and sometimes all three. Although often soft and 
earthy, it is sometimes so compact that it can be used for 
building purposes; and for this purpose it is used either in 
the rough state, or sawed into blocks of the desired size 
and shape. 

The mineral chalk can be burned into quicklime, and 
converted into cement or mortar. This mortar is used in 
the construction of many of the houses in London, and 
other places where chalk is found in abundance. 

The chalk cliffs and fields constitute a rock formation 
of vast area, along the shores of the North Sea and 
the English Channel, in France and England. These cliffs 
tower up in some places to a height of one thousand feet. 

Their white brilliancy in the sunlight presents a beau¬ 
tiful and dazzling appearance; and when viewed at night 
by moonlight, they present a weird, spectral and beautiful 
sight. 


9 



10 


THE TEACHER'S AID. 


England obtained the name Albion from the white chalk 
cliffs along its shores. 

Chalk is used for a variety of purposes; it is easily con¬ 
verted into lime, in which state it forms a valuable fertil¬ 
izer, as well as a cement. It is used as a marking material 
by tailors, carpenters, and artists, and in the manufacture 
of a preparation for the polishing of metals and glass. 

The silicious particles of chalk are easily separated by 
pounding, and diffusing in water, and in this way become 
whiting, the domestic uses of which are well known. 

The use of chalk in the form of crayons is well known; 
their application being chiefly confined to the public school 
rooms, the lecture room and the art schools. 

Chalk, when perfectly pure, is mixed with vegetable 
coloring matter such as turmeric, litmus, saffron and sap- 
green, in order to form pastile colors; but the vegetable 
colors that contain acid are changed by the action of the 
chalk; in this way the various-colored chalks for drawing 
and marking purposes are obtained. 

Vienna White, used by artists, is simplv purified chalk. 
When thoroughly pure, it is known as prepared chalk, and 
is used medicinally for acidity of the stomach. The com¬ 
mon white chalk is used in the preparation of cosmetics, 
dentifrices, etc. 

Black Chalk is a mineral quite different from the com¬ 
mon white chalk, and receives its name, presumably, from 
its semblance to white chalk in feel, in soiling the fingers 
when touched, and in being used for drawing and writing 
purposes. 

This chalk has a slaty structure, is of a bluish or grayish- 
black color; it is easily broken or cut, and leaves a perfect 
black mark on white or colored paper, wood, cloth, etc. It 
is used for drawing purposes, and as a black color in paint¬ 
ing ; it becomes red when exposed to heat. It is essentially 


THE TEACHER’S AID. 


11 


a variety of clay, and derives its color from the carbon 
which it contains. 

Red Chalk is a hardened, clayey ochre, or red chalk-iron 
ore, consisting of chalk and much peroxide of iron. It is of 
a brownish-red color, and a slight slaty structure, and 
when broken it exhibits an earthy appearance; the coarser 
varieties are used by carpenters for marking wood, etc., 
and the finer kinds are used by artists. Red Chalk occurs 
in bed formations in some parts of Germany. 

French Chalk is a popular name for steatite, or soap¬ 
stone; it is a soft magnesian mineral. 

Large quantities of chalk are annually converted into 
crayons, and consumed in the public schools, colleges, etc. 
For general work the natural white color of the chalk is 
retained, but for ornamental and artistic work coloring 
matter is introduced into the chalk before it is formed into 
the crayons. 

When the manufactured crayons are completed, they are 
packed in wooden boxes, and in this form are ready for the 
market. They are usually quite inexpensive. 

Note: Remarks on cost, uses, manufacture, etc., of 
chalk. 

£ j* 

INK. 

Ink is a fluid used for printing, writing and stamping 
purposes. It is usually made of an infusion of galls, cop¬ 
peras and gum-arabic. The most important inks are 
Writing Ink, Printing Ink and Indian Ink. There are 
many colors of ink, as black, red, green, blue, yellow and 
purple. 

Black is the kind most used, and therefore the most 
important. It is made of galls, gum and sulphate of iron. 
Some of the black inks are of a bluish color when at first 




12 


THE TEACHER’S AID. 


applied to paper, but become a beautiful black when 
allowed to stand for a while. 

The colored writing inks, which are little used, are made 
from different chemical compounds, as Prussian blue for 
the blue and purple inks. Red inks, of two kinds, are 
made from Brazil wood, and from cochineal, or carmine. 

Indelible ink is valued for its durability, and its chief use 
is for marking and stamping linen, muslin, etc. It is made 
from Frankfort black, gum-arabic, water, oxalic acid and 
sufficient cochineal, or sulphate of indigo, to give it the 
desirable shade. Heat, cold, light, or even the application 
of water, does not affect indelible ink while all the other 
inks are more or less affected by them. 

Printing ink is a soft, thick, glossy compound, very 
unlike the other inks. It is made by boiling linseed oil in 
an iron vessel, then firing it and allowing it to burn for a 
short time. The burning gives it durability, and it is again 
boiled and a quantity of resin is added. Coloring matter 
is then added while the mixture is hot. Lamp black for 
black ink; lemon, orange and chrome for yellow, Prussian 
blue for blue; vermilion, lake and carmine for red, and so 
on according to the color of ink desired. 

This mixture is then cooled and worked into a smooth 
paste. Printing ink is not in a fluid state, as the others 
are. India ink is made of a fine grade of lampblack, size 
or animal glue, and a small amount of perfume. 

In China, camphor forms one of the ingredients, and is 
thought to improve the quality of the ink. The Chinese 
use brushes in applying this ink in writing and printing. It 
is also used in making artistic designs in black and white. 

Sympathetic ink is a chemical compound used for 
writing, but which shows no color until acted upon by 
other forces, such as the application of heat, or chemical 
action of some kind. In this way the writing is made to 


THE TEACHER'S AID. 


13 


appear, but usually disappears upon the removal of the 
heat or chemical force. Sympathetic ink, like the 
other inks, is of various colors, as black, yellow, green, 
blue, etc. 

Writing ink is usually done up in glass bottles and stone 
jars, or jugs, and closed with cork or wooden stoppers. 
Indelible ink is sealed up air-tight. And printer’s ink is 
made up into balls or sticks and wrapped up in paper. 
Large quantities of the different varieties of ink are manu¬ 
factured and consumed annually. 

Remarks on the uses of the different inks, quantity 
used, cost, etc. 

BREAD. 

Bread is the name applied to the dough made by moist¬ 
ening the flour or meal of some species of grain, kneading 
it and baking it in some kind of an oven; in the mixing, 
some kind of fermenting matter is usually added, although 
not always. 

When fermented, it is known as leavened bread, and as 
unleavened when no fermenting substance is used. The 
earliest and most primitive way of making bread was by 
soaking the grain to be used in water, pressing it and 
drying it either by natural or artificial heat. 

An improvement on this method was made by “bray¬ 
ing” or grinding in a mortar, or between stones, before 
heating and miostening. The word bread is supposed to 
be derived from bray or brayed. 

This method was succeeded later by a more extensive 
bruising or grinding of the grain, which led to such simple 
forms of bread as the oat-cakes of Scotland; these are pre¬ 
pared by moistening the coarsely bruised oats, or oatmeal, 
with water, adding a proper amount of common salt, 


14 


THE TEACHER’S AID. 


kneading, rolling into thin sheets, and baking on hot platee 
or griddles suspended above a fire. In a similar way ths 
barley and pease-meal bannocks of Scotland are made. 

In the East Indies, as well as in Scotland, flour is mixed 
with water and kneaded into scones. A similar prepara¬ 
tion of wheat flour, in which the sheets of dough are made 
much thicker, forms the dampers of Australia. The pass- 
over cakes of the Israelites are prepared in this way. 

Indian corn meal, mixed with water and baked, forms 
the corn-bread of America. 

The above mentioned kinds of bread are known as 
unleavened, as no leaven has been added to produce fer¬ 
mentation. Leaven was used in the time of Moses, and it 
is probable that the Egyptians were the first to use it in 
the making of bread. 

This knowledge passed from the Egyptians to the 
Greeks, and from the Greeks to the Romans, who spread it 
through the northern countries during their invasions. 

The use of leaven has become so popular that it is used 
in the making of almost all kinds of breads and cakes at the 
present time. The flour made from wheat is generally used 
in the making of bread among the better classes, although 
rye, barley, rice and Indian corn flours are also extensively 
employed. 

These grains are composed of gluten, albumen, starch, 
gum, sugar, saline matter and fibre. The ratio of these 
ingredients varies, and they can easily be separated from 
each other by the application of water, or water and heat. 

In order to prepare these grains for use in the manu¬ 
facture of bread, they are subjected to the process of 
grinding, for the purpose of reducing them to a powder, 
and at the same time separating the hard indigestible 
particles. 

As the wheat is changed into flour by the process of 


THE TEACHER’S AID. 


15 


grinding, it assumes nearly twice its proportion in bulk. 
Wheat flour, which is the most important grain flour, is 
divided into many grades. 

Yeast is the fermenting power used, and in the process 
of bread-making the flour is mixed with water, and the yeast 
and a proper amount of salt is added; or the salt and yeast 
are mixed with the water first, and the flour added last. 

The mixture is thoroughly beaten until it assumes a 
ropy consistency. In this form it is known as sponge; it is 
placed in the kneading pan or trough and set in a warm 
place to raise, which process is known as “setting the 
sponge.” 

In a short time the heat causes the yeast to act upon 
the gluten, starch and sugar in the flour, causing their 
conversion into alcohol and carbonic acid gas, which are 
eventually diffused throughout every part of the dough, 
causing it to become very much inflated. 

When the fermentation has advanced to the desired 
stage, the baker adds more flour, and, if needed, more water 
and salt, and subjects the mass to a thorough kneading 
until it is of a thick, tough consistency. 

This raising and kneading process may be repeated 
again, but care should be taken not to allow the fermenta¬ 
tion to proceed so far that the dough will become sour, in 
which case it may collapse, and even if it does not, it is not 
so palatable. 

When sufficiently light, the dough is divided into a 
number of pieces of equal size, formed into loaves, and 
placed in tin or iron pans to raise; when sufficiently light, 
the loaves are placed in an oven which has been heated to 
the desired temperature, and baked. 

After baking for the proper length of time, which varies 
according to the size of the loaves and the temperature of 
the oven, they are removed from the oven, and also from 



la 


THE TEACHER’S AID. 


the pans, and allowed to cool. In this form they consti¬ 
tute the bread of commerce, and should have a brown 
outer crust and a white, flaky inside. Bread forms one of 
the chief articles of diet, and is called the “staff of life.” 

Improvements are constantly being made in the manu¬ 
facture of bread, as in the varieties of yeast used in fermen¬ 
tation, in the kind of flour used, and in the ovens used for 
baking. In fact, the present methods are much superior 
to the primitive ways employed in the manufacture of 
bread. 

The processes that apply to the manufacture of bread 
from wheat flour also apply to its manufacture from the 
various other grain flours. 

Bakers often add alum to their dough in order to 
increase its whiteness and give it a more pleasing appear¬ 
ance. But bread thus treated is considered unhealthy, 
and in many places the use of alum by bakers has been 
forbidden. In many cases the taste of the alum can 
readily be detected. 

Attention is often called to the Bread Fruit, which is 
the product of a tree which is a native of the islands in the 
Pacific and Indian Oceans. It is considered one of nature’s 
most important gifts to the inhabitants of those islands. 

The fruit of this tree forms the principal part of their 
food, and the inner bark forms material for a part of their 
clothing; its timber is employed for building and other 
purposes, and the juice forms a favorite beverage. 

The fruit of this tree is generally oval, or nearly spher¬ 
ical, and about the size of a large cocoanut; it is covered 
with a rough skin, which is marked with small squares or 
lozenge-shaped divisions, having a slight elevation in the 
middle. 

At first the fruit is green, but as it matures it becomes 
brown, and when perfectly ripe is of a rich yellow color. It 


THE TEACHER'S AID. 


17 


contains a fibrous pulp, which becomes juicy and yellow 
when perfectly ripe, but then has a disagreeable, rotten 
taste, and is unpalatable. 

The fruit is gathered for use before it has reached a 
stage of ripeness, in which case it has a white, mealy pulp, 
which very strongly resembles new made bread. 

This fruit may be preserved for use in various ways, 
and when baked will remain fit for use for a long time. 

Remarks on the uses of bread, manufacture, cost, etc. 

jt 

COFFEE. 

The coffee of commerce is the berry or seed of a tree 
belonging to the genus Coffea, which grows in Arabia, 
Persia and in the warm climates of Asia and America. 
Coffee is also the name applied to the beverage made by 
infusing the berry of the coffee plant in water, after it has 
been burned and ground. 

The coffee plant attains a height of fifteen or sixteen 
feet, and sometimes even as high as thirty feet. But its 
growth is usually retarded to five or six feet for the con¬ 
venience of gathering the fruit. 

The stem is upright and covered with a light brown 
bark, or, in some cases, grayish-colored bark. The branches 
are horizontal and opposite, crossing each other at every 
joint and forming a sort of pyramid. The flowers grow in 
clusters at the root of the leaves, around the branches. 
They are pure white, and of an agreeable odor. 

The fruit, which is a berry, grows in clusters along the 
branches and under the axils of the leaves. When the 
coffee plant is cultivated, its growth is checked by topping; 
the slender and pliant stems and branches then spread out 
and bend downward like the branches of the apple tree. 


2 


18 


THE TEACHER'S AID. 


In the cultivation of coffee the plants are raised from 
seeds in nurseries, and when a year old are transplanted in 
rows. In three years after they are transplanted, if they 
have received proper care, they begin bearing, and with 
proper care will continue to do so for twenty years, or 
even longer. 

The plant is an evergreen, and the foliage is always 
fresh and green; it blossoms continuously, although the 
flowers at some seasons are scarcer and more scattered. 
Thus the blossoms continue to put forth while the fruit of 
former blossoms is maturing; and the ripe and partially 
ripe fruit and the blossoms may be seen mingled at almost 
any season of the year. But there are two real harvest 
times in the year. 

The fruit, when ripe, becomes red and finally purple. 
In appearance it is very much like the cherry, and the 
fleshy part around the seeds is very sweet and palatable. 
Each fruit contains two seeds or beans, which constitute 
the coffee-bean of commerce. These beans are in the 
center of the pulp, and have the flat sides opposed to each 
other; they are separated from each other by a portion of 
the pulp, and also by a thin, tough membrane, which 
closely envelops them. 

As the fruit dries, the pulp forms a sort of shell or pod; 
this shell is removed by crushing, in order to prepare the 
seed for market. 

In the West Indies the fruit is picked by hand at inter¬ 
vals during the season of harvest. But in Arabia, where 
no rains prevail, it is allowed to remain on the tree till 
ready to fall, and is then shaken off upon cloths spead 
upon the ground to catch it. The perfect ripeness which 
the coffee in this country is allowed to attain may be one 
of the reasons for its very superior quality. 

When picked, it is next dried in the shade, and the pulp 


THE TEACHER'S AID. 


19 


is removed by hand. In the East and West Indies the 
curing is usually done by exposing a layer of fruit several 
inches in depth to the heat of the sun, so that fermentation 
takes place. When the fruit has become dried, it is passed 
between rollers, and the pulp is washed away. 

The tough membrane is separated after the seeds are 
dry, by a similar process, with a heavy set of rollers, and 
the chaff is removed by winnowing. 

The quality of coffee is greatly improved by age. The 
best coffee of commerce is said to be the Mocha, and next 
to this the Java. 

The raw coffee-beans are tough, horny and difficult to 
reduce to a powder, and consequently they require a 
preparative roasting before they can be ground or pulver¬ 
ized. And in order to make the ingredients of coffee 
soluble in water, they are roasted. 

The process of roasting should be stopped when the 
beans are a chestnut brown. When the roasting is com¬ 
pleted, the beans have lost about twenty per cent, in 
weight and gained fifty per cent, in bulk. 

When the roasting is completed, and the beans are 
removed from the fire, the vessel in which they were roasted 
should be kept closed till the beans have become cold. In 
this way they retain the aromatic flavor, which would 
otherwise become lost if the vessel had been uncovered 
when the roasting was completed. 

Roasted coffee may be injured by absorbing the odor 
of other substances; and even the raw coffee is liable to be 
damaged in this way. And it has been found detrimental 
to ship it in vessels that have previously been loaded with 
sugar, spices, etc. A few bags of pepper have been known 
to spoil a whole cargo of coffee. Freshly roasted and 
ground coffee, when tied up in linen bags, has been known 
to cause spontaneous combustion. 


20 


THE TEACHER'S AID . 


Coffee is used chiefly as a beverage, but it is also used 
medicinally. It is recommended in cases of whooping 
cough and as a palliative in violent spasmodic diseases 
attended with palpitation of the heart, rapid pulsation, 
and in hysterical affection, etc. Roasted coffee acts as a 
powerful deodorizer, and will rapidly destroy any noxious 
smell. 

The principal coffee-producing countries are Brazil, 
Java, Ceylon, Sumatra, St. Domingo, Cuba, Puerto Rico, 
Venezuela, Costa Rico, Mocha and the British West Indies. 
And the countries that consume coffee are United States, 
British Provinces, Germany, France, Switzerland, Italy, 
Holland, Belgium, Sweden, Norway and Russia. 

The price of coffee varies according to the quality, the 
supply produced, and the demand for the article. Some 
kinds are quite expensive, while others are cheap. It is a 
very important article of commerce, and large quantities 
are consumed annually. 

Note: Remarks on cost, uses, production, etc., of 
coffee. 

* 5 * 

SAND. 

“ Little drops of water, little grains of sand, 

Make the mighty ocean and the pleasant land.” 

Sand is a mass, or collection of fine particles of stone, 
particularly of silicious stone. It is not in the form of 
dust or powder, but is composed of small, round, or irregu¬ 
lar grains that vary in size, and make the grades of fine 
and coarse sand. 

It is hard, flinty and insoluble, but can be reduced by 
the action of heat. In its native state, sand is of a white, 
yellow, or grayish color; it is a heavy substance, and is used 
for a great many purposes, the most important of which 


THE TEACHER'S AID. 


21 


are: In the manufacture of glass, in pottery, in plaster 
and mortar; in the manufacture of artificial stone; for 
building and paving purposes; for making sand-paper, and 
for sprinkling the floors of public buildings. 

Note: Remarks on the cost, uses, etc., of sand, and 
where obtained. 

& 

RAISINS. 

Raisins are dried grapes, and are prepared by two dif¬ 
ferent methods. One method consists in cutting partially 
through the stems of the ripened bunches of grapes and 
permitting them, in this condition, to shrink and dry in 
the sun. 

These are by far the better grade, and are known as 
Muscatels, or “raisins of the sun.” The “sun raisins” of 
Malaga are the best in the world. 

By the other method the grapes are gathered, and either 
laid on floors or tables, or hung on lines in the sun to dry. 
And when dry, they are dipped in a preparation of hot lye, 
made by dissolving the alkali of wood-ashes with water, 
and adding to every eight or ten gallons of this lye a quart 
of olive oil and from a pound and a half to two pounds of 
common salt. 

After being dipped, they are put on screens of wicker 
work to drain, and are then constantly exposed to the sun 
for about three weeks. 

They are then picked from the stalks, although some 
are left on the bunches, and packed in boxes for the market. 

Spain, France and parts of Asia are raisin-producing 
countries. And California, also, produces a great amount 
of raisins. 

Compared with the common grape of colder climates, 
the raisin-producing grape is much sweeter, and contains 


22 


THE TEACHER’S AID. 


a greater amount of sugar. Large quantities of raisins 
are produced and used annually. 

Remarks on uses, cost, etc., of the raisin. 

WINE. 

Wine is the fermented juice of grapes and a few other 
small fruits. Grape wine is the most common. The juice 
is extracted by pressing the fruit, and when exposed to 
the heat and air, soon becomes fermented. 

Sugar is the principal ingredient in grape juice, and a 
quantity of sugar is often added, in order to obtain a 
stronger wine than the natural product. 

The quality of the wine is much affected by the extent 
to which the process of fermentation has been permitted 
to continue. When fermentation commences, the juice 
becomes turbid, and bubbles rise to the surface, and froth 
settles on it. This process varies, but in a moderate 
climate usually reaches its highest point in three or four days. 

But before it is finished, it is thoroughly stirred up, so 
as to re-excite the process. In two or three weeks the 
liquid becomes comparatively clear, and a sediment forms 
at the bottom. The wine is now removed from the sedi¬ 
ment and placed in another vessel, where a slow form of 
after-fermentation goes on for several months; the sugar 
being converted into alcohol and carbonic acid, and new 
sediment formed at the bottom. 

It is changed many times into different vessels, to get 
rid of the sediment. And when this is accomplished, it is 
ready for the casks or bottles. 

Wine improves by being kept in wooden casks, as the 
watery portion escapes by evaporation, and the strength 
of the other ingredients is relatively increased. 

The manufacture of wine has been carried on in all 


THE TEACHER'S AID. 


23 


countries where the grape could be successfully cultivated. 
Other varieties of wine, as Blackberry, Elderberry, Cherry, 
etc., are made in much the same manner as the grape wine. 

Wines are largely used for medicinal purposes, being 
used as a tonic and a stimulant. 

The wine-producing countries are France, Italy, Greece, 
Spain, Portugal, Germany, Australia and America. 

Remarks on cost, etc., of wine. 

«£* ^ & 

S T R AW. 

Straw is the name given to the stalks or stems of certain 
species of grain, pulse, etc., chiefly of wheat, rye, oats, 
barley, buckwheat and peas. When used in single or 
reparate stalks, it admits of the application of the plural 
noun straws. Collectively, it is known as straw. 

Straw, in the common acceptance of the term, means a 
mass of the stalks of certain species of grain when cut and 
threshed. 

It is used in the manufacture of straw-goods and paper, 
and as a food for cattle, horses and sheep. It is also used 
as a filling for mattresses, beds, pillows, etc., and as a 
packing around glassware, chinaware, bottles and other 
breakable objects, to prevent breakage while being handled 
and shipped. It is used in barns and stables as bedding 
for animals. 

A very important use is in the manufacture of straw- 
goods, which forms a very important and useful industry. 
The plaiting of straw seems to have been among the oldest 
arts practiced by man, and many specimens of early works 
in straw were found in the tombs of the Egyptians. 

The very earliest mention we have of the systematic 
application of straw plaiting in England is during the 
reign of Mary, Queen of Scots. The articles made at that 


24 


THE TEACHER'S AID. 


period were very crude; but the art has advanced to such 
a stage of perfection that at the present time most won¬ 
derful and beautiful straw creations are made. 

In the first stages of manufacture the plaits were made 
of the whole straws, that is, the round, unsplit straws. 
Articles made in this way were very heavy. 

Splitting the straw was next adopted; this w r as done by 
the use of a common knife, but this process was soon sup¬ 
planted by the use of machinery so arranged as to split 
the straws into many fine pieces. Some straws admit of 
being split much finer than others. 

A popular machine for splitting the straws is composed 
of a number of small, sharp blades set in a circular way 
around a stem, which terminates at one end in a handle, 
and at the other end in a small, sharp point. 

This point is inserted in the hollow of the straw, and on 
being pressed forward cuts the straw into as many pieces 
as there are blades on the instrument. The number of 
blades varies according to the size of the straws and the 
fineness of the work to be produced. 

When the whole straws are delivered to the manufac¬ 
turer, they are cut into even lengths, and the different 
thicknesses are sorted by means of sieves which are oper¬ 
ated by boys. 

These sieves have meshes of different sizes; the straws 
are first placed in the largest ones, through which the 
smaller straws pass, leaving the larger ones of a uniform 
size in the sieve. In this way the straws are passed through 
the succession of sieves, each of which retains a number of 
straws of a uniform size. 

When the different sizes are obtained, they are tied in 
bundles, in which form they are ready for the splitting 
machine. When split, they are made into braids and 
plaits of different designs, many of which are very com- 


THE TEACHER’S AID. 


25 


plicated and beautiful. This part of the work is usually 
performed by women and children. It can be dyed any 
color. 

The plaits and braids are next sewed or woven together 
in such a way as to form the article desired. The usual 
application of plaited straw is in the manufacture of straw 
hats; some of the finer grades of these goods are very 
expensive, while others are cheap. The price depends on 
the quality of straw used, and the design of workmanship. 

Large quantities of straw-goods are manufactured and 
used annually in almost all parts of the world where straw 
is produced. 

Note: Remarks on cost, uses, manufacture, etc., of 
straw. 

j* j* & 

SHOT. 

Shot is the term applied to all solid balls fired from any 
sort of firearms; those for cannon and cannonades being of 
iron, and those for small arms being of lead. The larger 
are known as bullets, and the smaller as shot. 

The shot used for guns at present, varies very much in 
size, being all the way from the three-pounders, for boat 
and mountain artillery, to the thirteen-inch shot, which 
weigh about three hundred pounds when used as shells, and 
seven hundred pounds when used as an elongated bolt. 
In the manufacture of shot, they are generally cast or 
moulded. 

Small shot is of various sizes, from swan-shot, which is 
nearly as large as peas, to dust shot, which is very small. 
It is made by dropping melted lead through a colander, 
which is kept in rapid motion. The shot drops from a 
considerable height, through the sieve, into cold water. 
The lead, after passing through the holes in these colanders, 
is in the form of small drops, or globules. 


26 


THE TEACHER'S AID. 


The holes in the colanders vary in size, according to 
the size of shot required. The colanders are in the form 
of iron hemispheres, and are about ten inches in diameter. 
They are coated on the inside with the cream or scum, 
which is taken off the metal. 

A small portion of arsenic is mixed with the lead, and 
the fusion in the colanders is kept up by means of a char¬ 
coal fire, which is applied to the outside of the vessels. 

Formerly, in the manufacture of shot, the lead passed 
from the colander through only a short space of descent 
into the water; the lead was then in a soft condition, and 
was slightly flattened by its contact with the water. It 
was soon discovered that there was great advantage to be 
derived from a long fall before the lead reached the water, 
as this enabled it to become hardened before its contact 
with the water. The smaller sizes require less distance, as 
they cool much more rapidly than the larger ones. Many 
shot towers, or factories, are very high, the highest one in 
existence being in the City of Villach, in Corinthia; in this 
factory the shot falls a distance of two hundred and forty- 
nine feet. 

When the shot has become cold, it is sifted through 
sieves having different-sized meshes, in order to separate 
the different sizes of grains. Sieves with large meshes are 
first used, the smaller ones passing through, and the larger 
ones of a uniform size remaining in the sieve; the grains 
which pass through this sieve are again placed in a sieve 
with a smaller mesh, and so on, till all the sizes are sep¬ 
arated. 

In the process of manufacture there are always more or 
less shot that are misshapen and unfit for use; these mis¬ 
shapen shot are found by their inability to roll when being 
sorted. They are melted and made over again. 

When the sizes are sorted, the next process consists in 


THE TEACHER'S AID. 


27 


polishing. This is done by placing them in small octagonal 
boxes, in which a small quantity of plumbago has been 
put; the boxes are then subjected to a rotary motion, 
which is continued till the shot have become bright and 
smooth. 

Note: Remarks on the cost, uses, manufacture, etc., 
of shot. 

JL 

PINS. 

Pins are small, sharp, pointed instruments made of 
metal, and used as requisites for the toilet and for pinning 
or fastening articles of cloth, paper, etc., together. 

They were first introduced about the latter part of the 
fifteenth century; they were first made of wire, but in 1850 
brass ones came into use. Several inventions were in use 
previous to this time for holding together parts of the 
clothing, etc. These articles were usually in the form of 
brooches, buckles, clasps, laces, hooks, etc. 

At first, in the manufacture of pins, they were made by 
taking a piece of wire of the proper length and filing a point 
at one end and then twisting a piece of wire around the 
other extremity, and fastening it solid, in order to form a 
knob or head. And ultimately these operations were so 
skillfully performed that a completely round head was 
made of very small wire which scarcely showed the nature 
of its construction. Some pins are still made in this way. 

It is surprising to learn how many operations are neces¬ 
sary to complete such a small article as a pin. These opera¬ 
tions are as follows: First, straightening and cutting the 
wire. This straightening is necessary as the wire, when 
made and drawn, is rolled up in coils on a cylinder, and 
when it is unrolled the coils still remain in shape. And in 
order to overcome this coiled shape, it is drawn through a 
machine constructed of upright iron rods, which com- 


28 


THE TEACHER'S AID . 


pletely straightens it. It is then cut in lengths of thirty 
feet, and these are again cut in the length required for 
four pins. 

The second process is known as pointing; this is done 
by two operators, each in charge of separate grindstones. 
The first is called the rough grinder, and the second the 
finisher. Each operator holds in his hand about thirty or 
forty of these straightened and cut wires, and by a move¬ 
ment of his thumb manages to make the wires turn round, 
so as to make a point on each as he holds them in his hands 
and against the grindstone; the second stone is of a finer 
material and gives then a finer finish. When one end has 
been pointed they are then reversed, and the other end is 
treated in the same way. 

The third operation consists in cutting the lengths of a 
single pin off these sharpened pieces. When the sharpened 
ends are cut off, the intermediate pieces are handed back 
to the pointers at the grindstones, and each end receives a 
point, and the pieces are again divided, this time into two 
pieces, and in this way the piece which was the length of 
four pins is reduced to the length of single pins, and each 
piece has one point. 

The fourth operation consists in twisting the heads. 
These are made of very fine wire which is coiled two times 
by means of a lathe, around another piece of wire of the 
same thickness as that of which the pin has been formed. 

The fifth operation consists in cutting the heads. The 
material for the heads of the pins being formed on the thin 
wire, it is handed to another workman, who cuts it off in 
small bits; the winding of the wire, and the cutting of off 
the heads, is done with great rapidity, as many as twelve 
thousand having been cut in an hour. 

The sixth operation is annealing the heads. This con¬ 
sists in softening them by putting several thousands of 


THE TEACHER'S AID. 


29 


them into an iron ladle or vessel, and making them red hot; 
they are then plunged into cold water. 

The seventh operation is stamping or shaping the heads. 
This consists in pressing the heads into a better shape by 
means of a small lever press, and at the same time fastening 
them on the pins. A rapid workman will put the heads 
on as many as twelve thousand to fifteen thousand in a day. 

The eighth operation consists in yellowing or cleaning 
the pins. This process consists in boiling them for about 
a half-hour in the dregs of sour beer, or a solution of argol 
or cream of tartar, and then washing them in clean water. 
This process is often called souring. 

The ninth process is known as whitening or tinning. 
For this purpose a large copper vessel is used, in which a 
layer of about six pounds of cleaned or yellowed pins is 
placed. Over this a layer of grain-tin to the amount of 
from six to eight pounds is spread. Several alternate 
layers of pins and tin are placed in the vessel, and then by 
a pipe which is arranged on the inside of the pan, water 
is gradually admitted. The water passes through the 
pipe to the bottom of the pan first, and rises gently 
through the different layers of pins and tin, but does not 
disturb them. Fire is next applied to the bottom of the 
pan, and when it has almost reached the boiling point, the 
surface is sprinkled with about a quarter of a pound of 
cream of tartar, and the whole mixture boiled slowly for 
half an hour. The contents of the vessel is then emptied 
into a strainer and shaken in order to separate the pins 
from the grain-tin and the liquid. By this process the 
pins have become covered with a thin coating of tin and 
instead of being yellow, as when they were placed in the 
vessel, they are now white. 

In the next, or tenth, process the pins are thoroughly 
washed in clean water. 


30 


THE TEACHER'S AID . 


The eleventh process consists in drying and polishing. 
And when washed and dried, they are put into a large 
leather bag, which also contains a quantity of bran, and 
are violently shaken back and forth. 

The twelfth process consists in separating the pins from 
the bran. This is done by means of fans. When this is 
done, the pins are completely finished, having a perfect 
head and point, and being smooth and bright. They are 
now ready to be placed in the papers. 

The thirteenth or last process consists in pricking the 
papers which are to receive the pins. This is done by 
means of a machine through which the papers are passed, 
and which at regular intervals, arranged according to the 
size of the pins to be used, pinches up a fold in the paper, 
and at the same time pricks the holes which receive the 
pins, and then places the pins in their proper positions. 
Formerly the setting of the pins was a separate operation. 
But machinery was devised that could set the pins as well 
as puncture the holes. Thus fourteen persons were 
required in the operation of making the completed pin. 
This is still the case in some of the smaller factories, but in 
all the large establishments machines are now used which 
make a great reduction in the amount of hand-work. 
These machines are so constructed as to perform the 
amount of work that formerly required many men, and 
consequently much more work can now be turned out in 
the same length of time. This lessens the cost of produc¬ 
tion, and consequently reduces the price of the finished 
article. 

Pins, although very useful and necessary articles, are 
very inexpensive. The price varies according to the qual¬ 
ity and finish of the pins. Pins vary in size from the tiny 
ones, which are scarcely a quarter of an inch in length, to 


THE TEACHER'S AID. 


31 


ones that measure from an inch to an inch and a half long, 
or even longer. 

Note: Remarks on cost, uses, manufacture, etc., of 
pins. 

J* j* j* 

PEPPER. 

Pepper is the name applied to a plant and its fruit. The 
pepper plant belongs to the genus Piper, of which there are 
many species. 

The most important species is the common or black 
pepper, which is a vine, or climbing shrub. It sometimes 
acquires a length of ten feet, and requires to be propped 
up in order to retain an erect position; props or small trees 
planted for this purpose being employed. 

The stems of the pepper plant are smooth and spongy; 
the leaves are broad, ovate and leathery; the flowers are 
white and grow in spikes; the fruit is about the size of a 
pea, green in color, changing to bright red as it becomes 
ripe; it is not crowded very closely on the flower-spikes. 

The common black pepper is a native of the East Indies 
and some of the Asiatic countries, but is cultivated exten¬ 
sively in many of the tropical countries. 

In the cultivation of pepper, the plants are obtained by 
means of cuttings. When the plants are three or four 
years old they begin bearing, and continue to do so for a 
period of ten or twelve years, yielding two crops annually. 

When any of the berries on the spikes begin to turn red, 
the entire bunch is gathered, because when permitted to 
ripen they are less fragrant and also liable to drop off and 
become lost, thereby diminishing the size of the crop. 

When the berries have been gathered, they are spread 
out on mats to dry, after which they are separated from 
the spike by means of rubbing or treading; they are next 


32 


THE TEACHER'S AID. 


thoroughly winnowed, which process removes all chaff, 
stems and impurities. 

When the berries have reached this stage, they are in 
the form of small, round, wrinkled, black grains, and con¬ 
stitute the unground, common black pepper of commerce. 
And when reduced to a coarse powder by means of grind¬ 
ing, it is known as ground pepper. 

White pepper is obtained from black pepper, by remov¬ 
ing the exterior coating of the berries. And in order to do 
this, the berries are soaked in water, and the outer part 
rubbed off. The product thus obtained is of a grayish- 
white color, which is often bleached almost white by the 
use of chlorine; the pepper thus obtained is of an inferior 
quality. 

Black pepper is much more pungent than white, as the 
essential part of the spice is more abundant in the outer 
part of the berries. 

There are numerous other species of the pepper plant, 
among which may be mentioned the Long pepper, a native 
of the East Indies; the cubebes, which are found in Java, 
Nepal, Sierra Leone and the Isle of France; and many 
others, all of which are used for the same purpose as the 
common black pepper. 

Pepper was known and used from very early times, 
being used by the ancients for medical purposes. 

During the middle ages is was considered one of the 
most expensive spices, and in the thirteenth century a few 
pounds of pepper were considered a valuable possession. 

Pepper is used medicinally as a local stimulant. When 
taken in small doses into the stomach, it has a very pleas¬ 
ant effect; but when taken in large quantities, it produces 
pain and irritation. Pepper is applied in the form of an 
ointment as a cure for ringworm. 

The amount of pepper consumed by the inhabitants of 


THE TEACHER’S AID. 


33 


the pepper-producing countries is much greater than that 
of the people in the countries where no pepper is produced. 

Pepper is not a very expensive condiment, but when 
ground it is often adulterated by the mixture of other sub¬ 
stances in order to cheapen it. Large quantities of pepper 
are consumed annually in all civilized countries. 

Cayenne or red pepper is the product of a plant known 
as capsicum. It is a small, shrubby annual or biennial 
with a partially woody stem; there are many different 
species of this plant. 

Capsicum is a native of the warm countries of Asia, 
South America and Mexico. It is, however, largely culti¬ 
vated in many sub-tropical countries. 

The pepper which is derived from the capsicum plant is 
very pungent, and is used as a seasoning for sauces, mixed 
pickles, etc. 

The pepper is derived from the pod, or fruit, of the 
plant, which in different species varies in size, shape and 
color; being round, oval, conical, long, heart-shaped, etc., 
and varying in size from the small, round, cherry-shaped, 
to the large, oblong, bell-shaped; the colors, when ripe, 
being different shades of red and yellow. The pods are 
green at first, but as they become ripe, they turn either red 
or yellow, according to the variety. 

When peppers are employed in the preparation of 
pickles, etc., they may be used either green or ripe; but for 
cayenne pepper only the red, ripe pepper and the seeds are 
used. The seeds often constitute the principal part, as 
they are the most pungent part of the fruit. 

Cayenne pepper is used medicinally for many purposes; 
it is highly valued as a condiment, and large quantities are 
consumed annually. 

It will be readily seen that the fruits from which the 
common black pepper and the red pepper are obtained are 


3 


34 


THE TEACHER'S AID. 


very much unlike, although they are derived from different 
species of the same plant. But ideas as to their source 
often become confused. 

Remarks on cost, uses, production, etc., of pepper. 

& j* 

GLASS. 

Glass is a hard, brittle substance, formed by fusing sand 
or similar substances with fixed alkalies. It is usually 
transparent, or nearly so, if properly freed from impurities. 
It is solid, lustrous, flinty and easily broken. 

The invention of glass dates back to very early times, 
and its invention is attributed to the Egyptians. The 
chemical composition differs in the different kinds of glass. 

The principal kinds of glass are: Window glass, which 
includes plate, sheet and crown; Bohemian crystal glass; 
flint glass, and bottle glass. There are a few other kinds, 
as optical glass and enamel glass, which are manufactured 
on a limited scale. 

The ingredients from which glass is made are: Silicia 
in the form of sand, rock-crystal, limestone, marble, chalk, 
spar and cullet or broken glass; also potash in the form of 
wood-ashes, pearl-ash and sulphate of potash; and soda in 
the form of carbonate, or sulphate of soda. 

All material used must be as free as possible from iron, 
copper and other impurities, if a clear glass is desired. In 
the manufacture of glass, the ingredients used are placed 
in the melting vessel or glass-pot. 

When filled, the glass-pots are placed in a furnace, and 
heat is applied. The heat is made intense enough to melt 
the ingredients in the pots, and when thoroughly melted it 
is skimmed and freed from all impurities. 

It is now in a soft liquid state and ready for the work- 


THE TEACHER'S AID. 


35 


men, who form it into bottles, vessels, etc., of the desired 
size and shape by means of the blow-pipe and moulds. 

In some furnaces the melting-pots are not used, the 
material being put directly into the furnace and melted. 
As the process of melting proceeds, the glass passes down¬ 
ward from the top of the furnace, through openings sup¬ 
plied with filters. The melted glass passes through, but 
all rough impurities are retained. 

This process is repeated until the glass is thoroughly 
melted and purified, and is then ready to be made into the 
desired articles. 

The moulds used are made of brass or cast-iron, and 
are made to be opened and closed by means of a spring. 
The hot glass which has been taken up by the blow-pipe 
and partly distended, is inserted in the top of the mould, 
and by means of blowing is made to fill the mould. The 
blow-pipe is a long, hollow iron tube. 

The glass articles, when shaped, are annealed in a hot 
oven to give them the desired strength. 

Glass is used for a variety of purposes. Its cost varies 
according to the kind of material used, and the skill and 
time employed, and the use to which it is to be applied. 

The most expensive kinds are optical glass, plate glass 
and cut-glass. Any of the varieties of glass can be colored 
any color or shade by the use of metallic oxides. 

Ground and colored glasses are used for decorative and 
ornamental purposes. Artificial gems, beads, buttons, 
ornamental windows, etc., are made of colored glass. 

Glass can be spun into fine threads or fibres, in which 
form it is quite flexible and can be woven into cloth. 

Note: Remarks on the cost, uses, etc., of glass. 


36 


THE TEACHER’S AID. 


FLOUR. 

Flour is the meal or more edible part of the different 
kinds of grain. In the United States it is customary to 
make a distinction between flour and meal; flour being 
applied to the finer products of wheat, rice, oats, barley 
and buckwheat, when separated from the bran, and the 
term meal being applied to the product of Indian corn. 
Flour is the popular name applied to the finer or pulver¬ 
ized portions of grain. 

The chief use of flour is in the making of breadstuffs for 
food. The earliest and most primitive way was to soak the 
grain in water and then press or crush it, after which it was 
dried either by natural or artificial heat. 

A rather more elaborate bruising or grinding gradually 
followed, which has been improved upon until the present 
perfect method of obtaining flour has been reached. 

The earliest method, and one whose date is unknown, 
consisted in crushing the grain between two stones. This 
device, which was known as a “ mill,” was composed of one 
large stone with a convex or hollow surface on one side 
and a smaller stone. 

The grain was placed in the hollow of the large stone, 
and pounded and ground with the smaller one, until it was 
of the desired fineness. 

This process was superceded by the use of the millstone 
in which stones similar to our modern millstones were 
turned by hand. 

Still later came the water-mill, whose motive power was 
a stream or flow of water on a large wheel, which caused 
the millstones to grind the grain. Wind has also been 
employed as a motive power. But steam power, applied 
to modern machinery, does the work now. 

Millstones have become displaced to a certain extent by 


THE TEACHER'S AID. 


37 


the application of the “roller process,” in which iron or 
porcelain rollers are used to crush the grain. 

By this process much more flour, and of a better grade, 
can be obtained from the wheat. It is possible by this 
process to convert into fine flour much of the material 
which, by the old process, was fit only for feeding to stock. 

During the process of grinding, the products obtained 
almost double the amount of wheat used. 

Many different grades of flour are produced, owing to 
the quality of wheat used and the process of manufacture. 

Flour forms one of the most staple articles of food, and 
large quantities are manufactured and consumed annually. 

Many states in the Union produce wheat in abundance, 
while others that are non-wheat producing must obtain 
their supply from the wheat-growing regions. In some 
cases the wheat is shipped into cities in the non-wheat 
producing sections and then manufactured into flour. 

The principal wheat-growing states in the Union are 
California, Minnesota, North Dakota, South Dakota and 
Iowa; while Illinois, Ohio, Indiana, Kansas and Nebraska 
produce this grain to a limited extent. 

The flour of rye, oats, rice, buckwheat, and also the meal 
from Indian corn, is made in much the same way as wheat 
flour. 

The price of flour varies according to the quality, the 
yield of wheat and the demand for it in the commercial 
world. 

Remarks on cost, uses, manufacture, etc., of flour. 

£ jit 

HONEY. 

Honey is the sweet juice secreted in flowers, from whence 
it is collected by the working, or neuter, bees. The bees 


38 


THE TEACHER’S AID. 


obtain the honey by means of a proboscis, which they 
insert in the flower. From the proboscis it is passed into 
the crop, or honey-bag, and when the bee returns to the 
hive the honey is disgorged into the cells of the honey¬ 
comb. 

Honey, when pure, is of a moderate consistency, and of 
a white color, tinged with yellow. It has a sweet taste 
and an aromatic smell. The best and newest honey is a 
clear liquid, contained in a white comb; while older honey 
is of a yellowish or even a reddish color. 

Honey is soluble in either cold or hot water, and will 
ferment in large quantities when not properly taken care of. 
The composition, quantity and quality of honey, is affected 
by the food of the bees, their age, the season, etc. 

The ingredients found in honey are sugar, mucilage in 
the form of gummy substances, odorous matter and pollen. 
The proportion of sugar increases with the age of the honey, 
causing it to become quite granular in time. 

The leading honey-producing countries are North 
America, France, Greece, Portugal and the West Indies. 
From ancient times honey has been used as an article of 
food. It was more valued then than now, as the use of 
sugar was unknown. 

Honey is very nutritious if taken in moderate quan¬ 
tities. It is used as a food, in the manufacture of medi¬ 
cines for coughs and colds, and in gargles for sore throats. 
It is also used as a flavoring for drinks and confectionery, 
and by some tobacconists to add sweetness to the tobacco. 

It is used by the bees for food, and constitutes a very 
important article of commerce. Large quantities are con¬ 
sumed annually. 

Adulterations are often mixed with honey, the most 
common of which are flour and gelatine. As there is a 


THE TEACHER'S AID. 


39 


large proportion of gelatine in honey, this adulteration is 
not so easily detected as the flour. 

To remove the impurities, the honey may be slightly 
heated, and when the impurities rise to the surface, which 
they readily do, they can be skimmed off. Artificial honey 
is now manufactured, and it so closely resembles the natural 
honey as to defy, or almost defy, detection. 

The price of honey varies according to the quality. It 
is also affected by the amount produced, by the season, 
and by the locality. The use of honey as an article of food 
has a very injurious and poisonous effect on some people, 
causing severe cramps and colic. 

Remarks on artificial honey; on how bees are kept and 
how the honey is taken from the hive; cost, amount pro¬ 
duced, etc. 

IRON. 

Iron is a metal of a livid whitish or grayish color. It is 
the most common and most useful of all metals. It occurs 
more abundantly than any other metal, and in its native 
form it is chiefly found in meteoric stones and in certain 
platinum ores. 

But the so-called iron ores, as the sulphides, oxides, 
etc., are widely distributed. 

Internally it appears to be formed of little facets, and 
when broken exhibits a ragged or broken surface. It is 
hard, fibrous and susceptible of a high polish. 

Next to gold it is the most tenacious of all metals, and 
next to tin the lightest. It is very malleable, and can 
easily be hammered into plates when hot. And its ductility 
permits it to be drawn very fine. It has the property of 
magnetism, and is attracted by the lodestone, from which 
it acquires the same properties. 


40 


THE TEACHER'S AID. 


Iron ore is rarely found in masses, but in ores mineral¬ 
ized by different substances. This ore is distributed over 
almost every part of the earth. 

Iron ore in its native state contains a great many impur¬ 
ities, which are removed by the process of smelting. It is 
fused or melted by the application of very intense heat. 
Before melting, it forms into a soft, pasty condition, in 
which state it may be hammered, drawn or moulded into 
any shape desired. And by placing two pieces together, 
when in this condition, they can be hammered so as to 
unite and form one piece to all appearances. When red 
hot, it is readily forged into any shape, but at ordinary 
temperature it is not very malleable. 

In the manufacture of iron the ore is placed in a furnace 
and raised to a very high temperature by the application 
of fire, and gradually fused into a soft mass. 

Every twelve, and sometimes every eight hours, the 
metal is run off from the furnace by means of a tap-hole at 
the bottom of the hearth, into rows of parallel moulds, 
called “pigs,” which are formed in sand; hence the name 
“pig-iron.” The iron thus obtained is called pig-iron or 
cast-iron. 

Cast-iron is converted into malleable iron by being 
deprived of its carbon and deleterious ingredients. 

The ordinary process for the manufacture of malleable 
iron consists of refining, puddling, hammering and 
rolling. 

Steel is another variety of iron. It differs from malle¬ 
able iron by containing a varying proportion of carbon. 
When rich in carbon, it closely resembles cast-iron 
in composition, except that it is more free from 
impurities. 

Cast-iron, being the crudest, cheapest and most fusible, 
is used for the heavy portions of engineering work, such as 


THE TEACHER'S AID. 


41 


bed-plates, for machines, cylinders, columns, cisterns, 
low-pressure boilers, water and gas pipes, rollers, grinders 
and such like. 

A large quantity is consumed in the manufacture of 
hollow ware, which includes pots, pans and other cooking 
vessels. For all kinds of ornamental objects it is almost 
exclusively used, because its property of being readily cast 
into moulds gives it a great advantage on the score of 
cheapness. 

Malleable iron is largely employed for the innumerable 
variety of articles included under the general name “ hard¬ 
ware,” such as locks, keys, hinges, bolts, nails, screws, 
wire-work and the so-called tin-plate, etc. It is also much 
used for roofs and bridges of large size. 

Steel is used in the manufacture of edged tools, cutlery, 
heavy shafting, ties, rails, boiler-plates, etc. Large num¬ 
bers of steamships are now being built of steel. In fact, 
iron is an indispensable article in the various industries and 
manufactures. 

Note: Remarks on cost, uses, manufacture, produc¬ 
tion, etc., of iron. 

jt 

BUTTER. 

Butter is the oily or fatty substance contained in milk. 
It is separated from the milk by means of agitation, in close 
wooden or earthen vessels. 

The agitation or motion may be either in a rotary or in 
an up-and-down direction, and is produced by small pad¬ 
dles or dashers with holes through them, which are kept in 
motion in the milk, or by the rotary motion of the vessel 
containing the milk or cream. 

This vessel is known as a churn, and is usually a very 
simple contrivance, although quite an improvement has 



42 


THE TEACHER'S AID. 


been made over the earlier methods of obtaining butter 
from milk. 

The usual method for obtaining butter from milk is as 
follows: The milk, when fresh, is strained into earthen or 
tin vessels, and set in a clean place to cool. The cream or 
fatty portion, which is lighter, rises to the surface and is 
skimmed off. When a sufficient quantity for a churning 
has been obtained, it is put in the churn, which should 
always be clean, sweet and cool. 

The process of agitating or churning is begun and con¬ 
tinued until all the minute, fatty particles in the cream 
collect in lumps or masses. When all the fatty particles 
are thus collected, they form the butter, and are then 
removed from the milk and placed in a wooden or earthen 
dish and kneaded and washed with cold water until all the 
milk has been removed. 

When thoroughly washed, a quantity of salt is usually 
added in order to preserve the butter and also to make it 
more palatable. It is next divided and made into rolls of 
the desired shape and size, or put into moulds, which usu¬ 
ally hold a pound, and stamped with some pretty design; 
or it is packed in stone jars or wooden kits, and is then 
ready for the market. 

The process of churning must be conducted at a moder¬ 
ate rate, as the quality of the butter is affected by either 
too slow or too rapid motion. It is also affected by the 
place in which the milk and cream are kept. A cool, dark 
place, or a place where running water passes round the 
vessel, being the most suitable, as it allows the milk to cool 
without souring, and the cream rises thick and sweet. 

The care which the cows receive, the amount and kind 
of food, water and shelter, exert quite an influence on the 
quality and quantity of milk which they produce. 

It is important that all vessels used in the care of milk 


THE TEACHER'S AID. 


43 


and cream, and in the handling of the butter, should be 
clean and sweet. Also that the air in the room or cellar 
where they are kept is pure, as cream and butter readily 
absorb impurities from other substances and from the air. 

In creameries, where large quantities of butter are made, 
the work of both churning and working the butter is done 
by machinery. Coloring matter is often introduced into 
the butter when it is of a light color. This coloring matter, 
while it is not at all injurious, gives it a bright and pleasing 
appearance, and is often a benefit in securing sale for the 
butter. The quality of pasture upon which the cows feed 
is said to affect the color. 

Butter forms an important article of food, and is one of 
the leading products of some sections of the country. 

Vegetable butter is the name given to certain concrete 
fats contained in some vegetable substances, and which 
remain solid, or of the consistency of butter, at ordinary 
temperature. The cocoanut and the peanut contain this 
butter in large quantities. 

It is obtained by crushing the burs and subjecting them 
to the action of hot water. Then cooling and removing the 
fat or butter; or by the application of heat and pressure. 

Remarks on substitutes for butter, uses, prices, etc., of 
butter. 

{^8 

ISINGLASS. 

Isinglass is a substance consisting chiefly of gelatin, 
and is obtained from the air-bladders of certain fishes. 
Most people consider isinglass as a mineral production, but 
such is not the case. It is of a whitish, almost transparent 
color, and has a very fine texture. 

This substance was at first obtained only from the stur¬ 
geon, a species of fish which inhabits the Caspian sea and 


44 


THE TEACHER’S AID. 


its tributaries. But it was found that the same part of 
many other fishes made good isinglass. 

The sturgeon is a large fish, averaging twenty-five feet 
in length, and it is said to take the bladders of five or six of 
these large ones to make a pound of isinglass. 

Russia was the only country from which isinglass was 
formerly obtained. But large quantities are now pro¬ 
duced in North and South America and in the East Indies. 

The appearance and structure of isinglass often causes 
it to be taken for a mineral production. Its resemblance 
to mica is so very striking that it is frequently mistaken for 
that mineral. 

It is used for an agglutenate and for refining wines and 
other liquors; it is also used in the fancy fronts of stoves. 
Heat does not destroy or affect it in any way, and it permits 
the fire-light to reflect through it, thereby causing a bright 
and cheerful light. 

Remarks on cost, uses, appearance, etc., of isinglass. 

jt & 

BRICK. 

Brick is a variety of stone made from baked clay. The 
usual form in which bricks are made is that of a parallelo- 
piped about nine inches long, four and one-half wide and 
three inches in thickness. 

The art of making brick dates from very early times. 
History shows that brick was used in the building of the 
Tower of Babel, and the walls of various other buildings 
of ancient Babylon were made of burned brick. The art 
of brick-making formed the chief occupation of the Israel¬ 
ites in the early times in Egypt. 

The brick which were made in early times were made 
of clay mixed with chopped straw, and were, in all proba- 


THE TEACHER’S AID. 


45 


bility, dried in the sun. From 1784 to 1850 all brick made 
in England were subject to taxation. 

The quality of the brick depends on the kind of earth 
used and the care with which they are fired. There are 
three principal classes of earth used for the making of 
brick—the pure clay, loam or sandy clay, and marls or 
earths which contain a varying portion of lime. 

The process of brick-making varies somewhat in differ¬ 
ent localities. The usual method being to reduce the 
earths from which the bricks are to be made to a thick 
paste by the use of water and machinery. 

This pasty earth is then pressed into moulds of the 
desired size and shape. When removed from the moulds 
they are dried for a short time in the drying house, where 
artificial heat is sometimes applied in order to hasten the 
process. 

When sufficiently dry to be handled without losing 
their shape, they are removed from the drying house and 
placed in a kiln which is built for the purpose of completing 
the drying process. When the kiln is filled the doors are 
closed, and fire is applied by means of fire-holes which are 
situated at intervals around the base of the kiln. 

When sufficiently dried, the fire is removed, and the kiln 
is allowed to remain closed for a short time, or until the 
brick have become sufficiently cool to be handled. When 
removed from the kiln, they are hard, solid, partially 
porous, and can be handled with ordinary care without 
danger of breakage. 

In the undried or unbaked form they are of a mud color, 
but when the process of burning is completed they have 
assumed a reddish or a reddish-yellow color, and are hard, 
and have a metallic ring. 

When removed from the kilns, they are usually stacked 
in piles in the brick-yard, and are then ready for the mar- 


46 


THE TEACHER’S AID. 


ket. Some bricks are used in the unglazed form, while 
others are glazed. The glazed varieties are more durable, 
as they resist the action of the elements better than the 
unglazed ones. The glazed ones are also much more 
expensive. 

Brick is largely used for building purposes, for pave¬ 
ments, etc. The manufacture of brick is a very important 
and useful industry, and large quantities of brick are 
manufactured and used annually. 

Note: Remarks on cost, uses, manufacture, etc., of 
brick. 

£ & 

BROOM-CORN. 

Broom-corn is a variety of grass cultivated in North 
America for the manufacture of brooms and whisks. 

It is regarded as a variety of the same specie to which 
sugar cane belongs, and has been much longer cultivated 
in North America than cane. 

A field of broom-corn presents a beautiful appearance 
when nearly ripe. It attains a height of from ten to twelve 
feet, surmounted by a bushy top covered with seed. The 
top panicles are green, but as they ripen they become 
light in color, and the seeds become dark. The stalk is 
hard and smooth, and usually made use of as a fertilizer, 
although cattle will eat it before it is affected by frost. 

The leaves are used for feed for cattle, and the seed for 
poultry, and often for horses and cattle. In the harvest 
of broom-corn the stalks are bent from two to three feet 
above the ground and allowed to remain in this position for 
a few days to dry. They are then cut, six or eight inches 
below the panicles, and laid in heaps on the ground. 

They are next collected and taken to the scraper, which 
is a machine employed to remove the seeds. It is a ma- 


THE TEACHER'S AID. 


47 


chine run by horse power, and so arranged that when the 
panicles or bunches of seeds are held in it, they are switched 
and beaten off. When the seeds are removed it is done up 
in bales and is then ready for sale to the broom manufac¬ 
turer. 

The price of broom-corn varies in value according to 
quality, from twenty dollars per ton up to as high as one 
hundred and thirty dollars per ton. Immense quantities 
are consumed annually. Some sections of the United 
States produce large quantities of broom-corn. 

Remarks, etc. 

£ jt 

BRANDY. 

Brandy is the name generally applied to a certain kind 
of ardent, spirituous liquor, which is obtained by the distilla¬ 
tion of wine. It is usually obtained from the juice of the 
grape, but peach brandy, apple brandy and some other 
kinds are manufactured to a large extent. 

Brandy may be distilled from any wine, but the red 
varieties yield a much less pure and a less aromatic spirit 
than the lighter-colored wines. 

The fermented liquors or wines employed for this pur¬ 
pose are numerous, and contain alcohol in a proportion that 
varies from ten to twenty-five per cent of their own weight. 
The red wines usually yield a larger proportion of alcohol, 
but that which is obtained from the lighter-colored varieties 
has a much finer flavor and a more agreeable taste. 

One thousand gallons of wine will yield, by distillation, 
from one hundred to one hundred and fifty gallons of 
brandy, which varies in degrees of strength according to 
the quality of wine used. 

This pure brandy is usually diluted with water until it 


48 


THE TEACHER'S AID. 


contains only from fifty to fifty-four per cent, pure alcohol. 

Brandy is a clear, colorless liquid when freshly distilled 
and, if intended to remain this color, it is stored in glass 
vessels; but if intended for colored brandy it is put in 
wooden casks or barrels from which the spirits absorb the 
coloring matter. The color is also increased by the addi¬ 
tion of burnt sugar and other coloring matter; and in this 
way the manufacturers and dealers impart to their brandies 
the varying shades of color. 

Fictitious strength is sometimes given to brandy by the 
addition of grains of paradise; and an astringent taste is 
imparted by the use of oak-bark and some other ingre¬ 
dients. The pleasing aroma of brandy is due to the pres¬ 
ence of more or less fusil oil. 

Brandy is used medicinally in different forms and for 
different purposes; it is the form in which alcohol is admin¬ 
istered, both as an external and an internal remedy. 

Brandy acts as a stimulant, restorative, excitant and 
tonic, for which purpose it is used internally. Burnt brandy 
is obtained by igniting a small quantity of brandy and 
allowing it to burn for a short time; it may be reduced by 
this process one-third, one-half or even more, and becomes 
stronger the more it is reduced. Burnt brandy, to which a 
little nutmeg is sometimes added, is a valuable remedy in 
cases of diarrhea. 

For external use, brandy is employed for healing sores, 
in stopping hemorrhages or the flow of blood caused by 
injuries. For these purposes it is applied by placing a cloth 
well saturated with the brandy over the affected part. It 
is also applied externally to harden the skin on tender or 
blistered parts of the hands, feet or other parts of the body. 

The chief brandy-producing countries are the countries 
which manufacture the most and the finest wines, among 
which are France, Spain, Portugal and Italy. Some of the 


THE TEACHER'S AID. 


49 


countries of North and South America also produce brandy 
to a certain extent. Great Britain and Ireland prepare 
large quantities of brandy from ordinary grain alcohol. 

Pure brandy is a very expensive article, and owing to 
the manner in which it is adulterated it is difficult to obtain 
it in its pure form. 

Note: Remarks on the cost, uses, manufacture, etc., 
of brandy. 

jit j* 

GLUE. 

Glue is a tenaceous, viscid, gelatinous substance obtained 
from the skins, parings, bones, offal, etc., of animals, when 
they have been acted on by heat and water. Or in other 
words, it is the gelatinous part of the animal substance 
separated from the bones, flesh and other parts. 

Glue is obtained by much the same processes as those 
employed for gelatine. The chief difference being that the 
materials used are not so pure, and not so thoroughly 
cleaned, and are not handled with as much care as are the 
materials for gelatine. 

In the manufacture of glue, the refuse of slaughter 
houses, such as the heads, feet, hides, sinews, horns, and 
particles of offal meat are used. In the Eastern states, near 
seaboard towns, large quantities of glue are made from the 
refuse of the fish curing and packing establishments; the 
heads and offal parts being utilized. 

The fish glue factories are the source from which the 
liquid glue and crockery cement are obtained. 

The materials used in the manufacture of glue are 
washed and freed from dirt. The washing takes place in 
huge barrels, or tanks, that are made to revolve on shafts. 
The tanks are about half filled with the glue stock, and 

4 


50 


THE TEACHER’S AID. 


sufficient water, containing certain acids, added to cover it; 
the tank is then closed and made to revolve for a length of 
time sufficient to partially clean the materials which it 
contains. 

The pieces of hide having hair on are now separated 
from the meaty, and other particles, and are packed in vats 
with lime; here they are allowed to remain for about a 
week, being occasionally stirred with shovels. This process 
thoroughly loosens the hairs, and at the same time sepa¬ 
rates the fat, which, by the action of the lime, is converted 
into lime-soap. 

The glue stock is subjected to a second washing, which 
is much more thorough, and is performed in a much larger 
tank, where all traces of lime and hairs are removed; it is 
now ready for the boiling process. 

In the boiling process, water and heat are employed, and 
when the operation is completed, the liquid glue is drawn 
off from the bottom of the vat in which the boiling took 
place. 

The liquid obtained is about the color of bullion, or 
oyster broth, and a little coloring matter is now added. It 
is placed in galvanized iron pans which are three feet long 
by eight inches wide, where it is permitted to cool, or “ set, ” 
without becoming hard. 

The glue is removed from the pans by turning them 
upside down and applying heat to the bottom of the pans, 
which causes the glue to come loose in a solid cake, of a 
gelatinous consistency. 

These cakes are then passed along on slides where a 
series of wires have been stretched; these wires slice the 
cakes lengthwise into sheets about a half inch in thickness. 
The slices are placed on screens made of wire netting, and 
dried in a drying room, until they become perfectly hard. 
It is now in the form known as commercial glue. 


THE TEACHER’S AID. 


51 


When being prepared for the trade, the sheets are 
sometimes packed in barrels, but they occupy a great 
amount of space, and require a great deal of time and care 
in packing; and for these reasons it has been found more 
convenient to pass the sheets through crushers, which are 
so arranged as to make the pieces large or small as desired; 
they are then packed in barrels. 

The glue of commerce is obtained in both liquid and dry 
form. The dry glue is a hard, flinty substance when dry, 
but rapidly becomes soft when heat and water are applied; 
in this form it becomes liquid glue. 

Glue is yellow, or brownish-yellow in color, and semi¬ 
transparent; it dissolves in warm or cold water, but more 
readily in warm. And when dissolved, it becomes liquid 
glue, in which form it must be, to be used for any purpose. 

Glue factories are very foul smelling places, and it is a 
very courageous person who can make a visit of investga- 
tion or inspection to one of these places. Glue factories are 
usually situated on the outskirts of the city or village where 
they are located. 

The uses to which glue are applied are numerous. It 
forms an important ingredient in kalsomine and size, for 
use on walls, ceilings, etc.; it is indispensable in furniture 
factories, wagon shops, and pattern-rooms; and it forms a 
very important element in the composition of papier- 
mache, composition toy animals, printer’s rollers, and in 
the binding of books, magazines and the like. It is also 
used as a stiffening substance for different kinds of cloth 
and straw fabrics; in the manufacture of hats, Brussels 
carpets, and in many places where two pieces of cloth, 
paper, or wood are to be joined. 

Glue is a very useful, and almost indispensable article. 


52 


THE TEACHER'S AID. 


and large quantities are produced and consumed annually 
in the United States. 

Remarks on cost, uses, manufacture, etc., of glue. 

^ S & 

MACARONI. 

Macaroni is a paste, or dough, made from wheat flour, 
and formed into pipes, or tubes, of different sizes, varying 
from an ordinary quill up to those of an inch in diameter. 
But there is no real difference in its composition and that 
of the fine, thread-like vermicelli and the many other 
curious preparations that are included under the name of 
Italian pastes, and used in the making of soups. 

The manufacture of macaroni originated in Italy, and 
for a long time it was exclusively used in that country. It 
now forms a very important industry, and large quantities 
are manufactured both for home consumption and for 
export abroad. It is now manufactured in this country, 
Great Britian, and many other places. 

In the manufacture of macaroni, the varieties of flour 
that contain the most gluten should be selected. The 
wheat is ground into coarse flour, from which all the bran 
is removed. During the process of grinding, it is necessary 
to use both heat and water, in order to procure a good 
flour. 

This flour is then made into dough, by the use of water, 
and when of a proper consistency it is forced through 
gauges, or hollow tubes of the desired size. The paste 
passes out through the gauges while still in a soft state, 
but soon becomes hard and brittle by exposure to the air 
and heat. 

The finished macaroni is of a yellowish, or yellowish- 
white, color. The best grades arc those which are clearest 


THE TEACHER'S AID. 


53 


and whitest in color, and which do not break or muss up 
when boiled. 

During the process of cooking, it should swell consider¬ 
ably, but retain its form; when it does not do this, it has 
been made out of an inferior grade of wheat. 

It is a flat, tasteless substance until seasoned, when it 
becomes quite palatable. Some manufacturers flavor it, 
and color it with saffron and turmeric, in order to suit 
certain tastes; but this is a rare, rather than a common 
practice. 

Macaroni is used exclusively for culinary purposes; it is 
employed in many ways in the making of puddings, soups, 
etc., for which it is highly prized by many people. 

The price of macaroni varies according to the quality, 
but even the better grades are not expensive. Large 
quantities of macaroni are manufactured and consumed 
annually in the United States. 

Remarks on uses, manufacture, etc., of macaroni. 

& £ & 

NUTMEG. 

Nutmeg, which is a well known and favorite spice, is 
the kernel of the fruit of several species of Myristica; it 
consists chiefly of albumen. 

This tree belongs to a natural order of exogens, which 
consists of about forty species, all of which are tropical 
trees or shrubs, and natives of Asia, Madagascar, and 
America. 

They generally have red juice, or a juice that becomes 
red when exposed to the air. The leaves are alternate and 
without stipules. The fruit is succulent, yet opens like a 
capsule, by two valves. The seed is nut-like and covered 


54 


THE TEACHER'S AID. 


with a fleshy aril, and has an albumen penetrated by its 
membranous covering. 

The fleshy part of the fruit is rather hard, and is of a 
peculiar consistency, resembling candied fruit; it is often 
preserved and eaten as a sweetmeat. 

Within is the nut, enveloped in the curious yellowish- 
red aril, or what is known as the mace; and under this is 
a thin, shining, brown shell, which is slightly grooved by 
the pressure of the mace, and within this is the kernel, or 
nutmeg. 

The nutmeg yields by expression, a peculiar yellow fat, 
called oil of mace, because from its color and flavor it was 
supposed to be derived from the mace; and by distillation, 
the nutmeg yields an almost colorless fluid, or essential oil, 
which has a very strong flavor of nutmeg. 

Nutmegs are used chiefly as spices; but medicinally they 
are stimulant and carminative. They possess narcotic 
properties, and in large quantities produce stupefaction 
and delirium. 

The nutmeg of commerce is an oblong, hard nut of a 
brownish-gray color, with a white, powdery looking coat¬ 
ing, which easily rubs off. They are quite inexpensive, 
and large quantities are used annually for flavoring and 
other purposes. 

Note: Remarks on cost, uses, etc., of the nutmeg. 

MORTAR. 

Common mortar is a mixture of slacked lime and sand, 
with water. It is one of the most important lime cements, 
and is used for uniting stone and brick in walls. 

If the lime is freshly slacked, and the materials mixed 
with limewater, the cement will be much stronger. In 


THE TEACHER'S AID. 


55 


order to secure a fine, smooth paste, which is essential to 
good mortar, the lime should be slacked very rapidly by 
using about three parts of water to one of lime. 

If the quantity of water is not sufficient, the slacked 
lime produced is of a coarse quality. Mortar when used, 
is applied in a soft state, and hardens in whatever shape 
it has been applied, and with the objects which it unites, 
forms a solid mass. 

It is of a grayish color, and owing to the lime, is often 
very injurious to the skin and the eyes, if brought in contact 
with them. Its chief use is in the construction of buildings, 
walls, etc. 

Note: Remarks on uses, value, cost, etc., of mortar. 

jt jt 

PEARL. 

Pearl is a peculiar production of certain marine and 
fresh-water mollusea, or shell-fish. Most of the molluscous 
animals which are aquatic and reside in shells are provided 
with a fluid secretion, with which they line their shells, and 
give to the otherwise hard, granular material of which their 
shell is formed a beautifully smooth surface, which prevents 
any unpleasant friction upon the extremely tender body of 
the animal. 

This secretion is evidently laid on in extremely thin, 
semi-transparent films, which, in consequence of such an 
arrangement, have generally a beautiful irridescence, and 
form, in some species, a sufficiently thick coat, which can be 
cut into useful and ornamental articles. This material, in 
its hardened condition, is called nacre by geologists, and by 
dealers “ mother-of-pearl. ” 

Besides the pearly lining of the shell, detached and 
generally spherical portions of the nacre are often found on 


56 


THE TEACHER’S AID . 


opening the shell, and there is great reason to believe these 
are the result of accidental causes, such as the insertion of 
a grain of sand, or other substances, which, by irritating the 
tender body of the animal, oblige it, in self defense, to cover 
the cause of the offense, which it has no power to remove; 
and as the secretion goes on regularly to supply the growth 
and wear of the shell, the obtruding grain of sand receives 
its share and thereby continues to grow in size, until it 
becomes a pearl. 

The Chinese avail themselves of the knowledge of this 
fact to compel one species of fresh-water mussels to produce 
pearls. In order to do this, they keep them in tanks, and 
insert between the shells and the mantle of the animal, 
either small, leaden shot, or small spherical pieces of 
mother-of-pearl. These are sure to receive regular coatings 
of the nacreous secretion, and, after a while, look like 
pearls formed by ordinary circumstances. The exact 
nature of this secretion has never been satisfactorily 
determined. 

The most famous pearls are those from the East; the 
coast of Ceylon having from the earliest times been the 
chief location for pearl fishing. They are, however, 
obtained now, of nearly the same quality, in other parts of 
the world—as Panama in South America, St. Margarita in 
the West Indies, the Caromandel Coast, the shores of the 
Sooloo Islands, the Bahrien Islands, and the islands of 
Karak and Corgo in the Persian Gulf. 

All the foreign pearls used in jewelry are produced by the 
Pearl Oysters. The shells of the mollusks which yield the 
Ceylon, Indian, and Persian ones are sometimes as large as 
a foot in diameter, and are usually about nine inches. 
Those of the New World, although the shells are smaller and 
thicker, are believed to be the same species. 

The season of pearl fishing lasts about three months, 


THE TEACHER'S AID. 


57 


commencing about the mindle of February, and is carried 
on under government regulations. 

The boats vary in size from ten to fifteen tons burden; 
they put out at night, generally about ten o’clock. The 
divers are under the direction of a manager, and are chiefly 
Tamils and Moors, from India. 

Each diver is provided with a diving-stone, weighing 
about thirty pounds. This stone is fastened to a rope long 
enough to reach to the bottom, and having a loop made for 
the man’s foot; and in addition to this, a large net-work 
basket, in which to place the pearl oysters as he collects 
them. 

These articles are placed over the sides of the boat, and 
the diver, placing his foot in the loop attached to the stone, 
liberates the coils of the rope, and with his net basket 
rapidly descends to the bottom. To each boat there is 
usually allowed a crew of thirteen men and ten divers, five 
of whom are descending, while the others are resting. This 
work is done very rapidly, for, notwithstanding the stories 
to the contrary, the best divers cannot remain longer than 
eighty seconds below the surface of the water, and few are 
able to remain longer than sixty seconds. 

The greatest depth they descend is thirteen fathoms, and 
the usual depth is about nine fathoms. When the diver 
gives the signal, by pulling the rope, he is quickly hauled 
up, with his net and its contents. Accidents rarely happen. 
The divers are sometimes paid fixed wages; yet some agree 
to accept as compensation one-fourth the product of their 
labors. 

When a boat-load of oysters has been obtained, they are 
taken to shore, and the cargo, sometimes amounting to 
20,000 to 30,000 is landed and piled on the shore to die and 
putrefy, in order that the pearls may be easily found. 
The heaps of oysters are sometimes placed in small, walled 


58 


THE TEACHER'S AID. 


compartments, the walls surrounding each being about 
one to two feet in height. Several of these compartments 
surround a small central inclosure, in which is a bath, and 
they slope toward this bath, and are each connected with it 
by a small channel, so that any pearls washed out from the 
putrefying mass by the rain may be carried into the bath, 
from which they are easily secured. 

When the animals in the shells are sufficiently decom¬ 
posed, the washing commences, and great care is taken to 
watch for the soole pearls, which are always by far the 
most valuable. The shells are then examined, and if there 
are any attached pearls found to be adhering to the shells, 
they are handed over to the clippers, who, with pinchers 
and hammers, skillfully remove them. The pearls that 
have to be removed from the shells are used only for set¬ 
tings ; while the ones that wash loose, being usually round, 
are drilled and strung, and can be used for beads, etc. 
The workmen who are employed to drill the pearls, also 
round the irregular ones, and polish them with great skill. 

Pearls vary in size. The smaller ones are sorted into 
sizes, the veiy smallest ones being called “seed-pearls.” 
Pearls are also found in the fresh-water mussels of rivers. 
The pearls of this mollusk are generally small, badly 
colored, and often valueless; but occasionally they occur of 
such beauty as to rival those of the pearl oyster. 

The fishing for pearl mussels is by no means as danger¬ 
ous, or as troublesome, as fishing for the pearl oyster. 
Usually they are found in beds of streams shallow enough 
to wade into, and so clear they can be seen at the bottom. 
If too deep to remove with the hands, they are easily cap¬ 
tured by putting a stick between their opening shells, 
which instantly close upon it, when the stick is quickly 
withdrawn from the water with the mussel adhering 
to it. 


THE TEACHER'S AID. 


59 


Even the most inferior pearls have a market value; for 
pearls can only be properly polished with pearl-dust, and 
the inferior ones are powdered for the purpose of polishing 
and rounding the finer ones. 

False pearls are very admirable imitations, made by 
blowing very thin beads, or bulbs, of glass, and pouring 
into them a mixture of liqiud ammonia and the white 
matter from the scales of the Bleak, and sometime^ from 
the Roach, and Dace. 

The proper way to prepare the pearl-matter is first to 
remove the scales from the lower part of the fish; these 
must then be very carefully washed, after which they are 
put to soak in water, when the pearly film falls off and 
forms a sediment in the bottom of the vessel, which is 
removed, and placed in the liquid ammonia for future use. 

When used, it is diluted with liquid ammonia and in¬ 
jected into the glass beads so as to thinly coat them on 
the inside; afterwards, the better kinds are filled with 
melted white wax, which renders them much more durable, 
and heavier. 

The French and Germans produce, in this way, imita¬ 
tions of the finest oriental pearls, of such beauty that the 
most practised eye can hardly detect the difference. 

Note: Remarks on the cost, uses, etc., of pearl. How 
and where obtained. 

jt & 

GOLD. 

“Gold, gold, gold, gold, 

Hard to get, and heavy to hold.” 

Gold is a precious metal of a bright yellow color. It is 
the most ductile and malleable of metals, and the heaviest 
next to platinum. It has a bright metallic luster, and is 
almost as soft as lead. 


60 


THE TEACHER’S AID. 


In its native state it occurs in masses, usually in the 
form of cubes, plates or nodes. These masses or particles 
are called nuggets and are usually very small, but are 
occasionally found in large sizes. It is usually found 
mixed with silver, copper and iron. 

Gold appears to have been known from earliest times, 
and was probably one of the first discovered of metals. 
It has always been used as a medium of exchange, for 
ornamental purposes, jewelry, etc, and was used by the 
ancients for much the same purposes as those to which it 
is now applied. 

On account of its softness it is usually alloyed with 
some other metal, copper and mercury being the ones most 
used. Copper and gold can be mixed in all proportions 
without greatly affecting the color of the gold, the only 
difference being that it acquires a redder tint. The ductil¬ 
ity of gold is made less by alloying it with other metals, 
while by the use of alloys it is made much harder and 
more serviceable. 

Gold can be beaten into sheets, or leaves, as thin as the 
1-200,000 of an inch. One grain when beaten can be 
made to cover fifty-six square inches. Light will pass 
through a sheet of gold beaten to such a fineness. 

The ductility of this metal is very great, as one grain 
can be drawn out into five hundred feet of wire. It is 
more tenacious than silver, copper, iron or platinum. 

It fuses at an intense heat, and when melted can be 
moulded into any desired shape. It is a perfect conductor 
of electricity and heat. 

Gold is found widely diffused over the earth’s surface, 
but the most noted gold-yielding districts are the United 
States, Mexico, British America, Australia, and Africa. 
Gold mining forms a very important industry. 

The chief uses of gold are as a medium of exchange, or 


THE TEACHER’S AID. 


61 


as money, in the form of coins of various sizes and values; 
in the manufacture of jewelry, for ornamental purposes, etc. 

Gold-thread, used in making laces and other fabrics, is 
made of silk thread overlaid with plates of very thin gold. 
Gold wire is made of gold, or silver gilded with gold. 

The very fine particles that are collected in the mining 
and milling of gold are called gold-dust. The quantity of 
gold which is found and brought into use is very small in 
proportion to other metals. 

The extraction of gold from the other substances with 
which it is found, is affected more by mechanical than by 
chemical means, though both are employed. 

Note: Remarks on the discovery of gold in the United 
States. On the extraction and purifying of gold. On 
coining, values, etc. On other uses of this metal. 

^ 

LINEN. 

Linen is a fabric manufactured wholly from flax or lint. 
The manufacture of linen has reached its greatest perfection 
in France, Ireland, and the Netherlands, where the stimulus 
to produce fine yarns for the lace makers has given rise to 
such care and attention in the cultivation and preparation 
of flax, that in point of fineness of fibre they have been 
unequaled. 

The chief kinds of linen goods are lawn, damask, sheet¬ 
ing, toweling, duck, crash, and ticking. Some of these are 
very heavy, coarse, materials; again, some are of exceeding 
fineness. Some are bleached, and some are unbleached or 
nearly so. 

Linen yarn is used as warp for other materials. And 
when mixed with cotton makes a cheaper, although not as 


62 


THE TEACHER'S AID. 


durable an article. Linen is one of the most ancient 
of textile manufactures, and is noted for its great 
durability. 

Remarks on linen. 


MATCHES. 

Matches are articles prepared from inflammable materials 
for the purpose of obtaining fire or light readily. 

One of the first forms of this valuable article was the 
“ brimstone match ” made by cutting very thin strips of 
highly resinous, or very dry, pine wood about six inches 
long, having pointed ends, which were dipped into melted 
sulphur. When thus prepared, the sulphur points instantly 
ignited when applied to a spark of fire obtained by striking 
fire with flint and steel. 

This method of obtaining fire or light was in almost uni¬ 
versal use up to the end of the first quarter of the nineteenth 
century, when several ingenious inventions followed each 
other in rapid succession, and displaced its use completely. 
So that it would now be difficult to procure a bunch of 
brimstone matches. 

The first of these inventions was known as the “ Instanta¬ 
neous Light Box,” and consisted of a small tin box in 
which was placed a bottle containing a quantity of sul¬ 
phuric acid in which was placed enough fibrous asbestos to 
absorb the acid and prevent it from being spilled, and a 
supply of properly prepared matches. 

These matches consisted of small splints of wood about 
two inches in length, one end of which was coated with a 
paste made of the following mixture: six parts of chlorate 
of potash, two parts loaf sugar, one part powdered gum 
arabic; the paste, which was formed of the above ingredi- 


THE TEACHER’S AID. 


63 


ents and water, was colored with vermilion. These 
prepared sticks readily ignited when the prepared ends 
were dipped into the sulphuric acid. But the use of the 
sulphuric acid was a great disadvantage to this invention. 

The Lucifer match succeeded the above, and differed 
from it greatly, as the bottle of sulphuric acid was omitted. 
This match was either made of wood or small strips of 
pasteboard, and the inflammable compound was made of 
chlorate of potash and sulphuret of antimony, with enough 
pulverized gum mixed with them to insure the mixture, 
which was made of water, to stick. These matches were 
ignited by friction with sandpaper. The Lucifer match 
became very popular, and the name is still applied to more 
recent inventions. 

Next to the Lucifer came the Congreve, a modification of 
which is still in use. This match only required a slight 
friction to ignite it, for which purpose a small piece of sand¬ 
paper was attached to the box in which the matches were 
contained. 

The Special Safety Match and the Swedish Safety Match 
are among the latest inventions. There is always more or 
less danger of accidental ignition if matches are allowed to 
lie around carelessly. 

The square sticks, which have always proven the best, 
are cut very simply by two sets of knives acting trans¬ 
versely with each other. The round ones, which have the 
fault of being weak, are cut by perforated steel plates, 
which were invented in 1342. 

In these plates the holes are exactly the size of the 
splints; and the edges of the holes are sufficiently sharp 
that when pressed upon the transverse section of the wood 
they cut down through it. 

The various ornamental forms of matches made by the 
German match-makers, who excel in this manufacture, are 


64 


THE TEACHER'S AID. 


produced by planes, the irons of which are so constructed 
that they plough up splints of the form required. 

Until the introduction of red amphorus, the trade of the 
match-maker was extremely unhealthy. The trade in 
matches has reached enormous proportions, and large 
quantities are manufactured and consumed annually. 

The United States, France, Germany, Austria, and 
England are the countries that produce the most matches. 
Matches as now manufactured are quite inexpensive arti¬ 
cles, when we take into consideration the various processes 
through which they pass, and the great demand for them. 
They are one of the necessities of life, and are almost 
indispensable. 

Note: Remarks oh cost, uses, manufacture, etc., of 
matches. 

jit 

FUR. 

Fur is the name applied to the soft, fine, short hair of 
certain animals. It grows very close on the skin, and 
being soft and very fine, is readily distinguished from hair, 
which is longer and coarser. 

It is one of the most perfect non-conductors of heat, 
and for this reason garments made of fur are worn in cold 
countries as a protection against cold. 

Fur has been used as an article of clothing from early 
times; this causes a great demand for fur in some localities, 
which has led to the diminishing of some and the utter 
extinction of other fur-bearing animals. North America, 
particularly the colder parts, has become the chief fur- 
producing country, although Asia and South America 
yield valuable furs. 

Among the leading fur-bearing animals may be named 


THE TEACHER’S AID. 


65 


the seal, sable, ermine, marten, silver fox, red fox, otter, 
sea-otter, beaver, chinchilla, squirrel, hare, rabbit, musk¬ 
rat, badger, mink, lynx, bear and raccoon. 

The fur produced by these animals varies in color, 
ranging from white, as that of the ermine, to the different 
shades of gray, red and brown to coal black, as that of the 
black bear. 

Furs are classified as felted and dressed. The felted furs, 
to which class the beaver, hare and rabbit belong, are made 
into a felted fabric, which is used in the manufacture of hats. 
In this fabric the hairs, or fibres, are very closely interlaced. 

Dressed furs are those to which the furrier’s art is ap¬ 
plied. This variety is used in the manufacture of muffs, 
boas, caps, coats, jackets and other garments, and as fur 
trimming for hats, jackets, dresses, etc. 

In dressing the skin, the fur is not separated from the 
pelt, which leaves a good foundation for the dressed fur. 
'While for the felted variety, the hair and pelt are separated, 
only the hair being made use of. 

On many of the fur-bearing animals the hair is of two 
kinds: A short, close layer next the pelt, which is used for 
felting purposes, and a longer layer, which is not used. 
The long hairs are removed by the use of a knife which 
resembles a cheese-cutter; this is a process which requires 
much care and skill. In some cases, and with certain 
kinds of skins, the hair is removed by pulling, instead of 
clipping. 

On account of the oiliness of some pelts, a cleaning 
process, in which boiling water and soap are employed, is 
necessary; in some cases repeated washings are necessary, 
owing to the degree of oiliness. 

Skins which are taken from the animals in the Winter 
season produce the best grade of fur, and is known as 


66 


THE TEACHER'S AID. 


seasoned fur, while that produced during the warmer part 
of the year is known as unseasoned. 

In the preparation of fur, the skins go through various 
processes of cleaning and soaking in order to remove the 
natural oiliness, odor and dirt. Water, soap, alum and 
soda are used, and when cleaned and dried the pelt has 
been converted into a sort of leather. 

The skins are now ready for use, and are made up into 
garments of the desired shape and size. In order to do 
this, the skins are cut in pieces and sewed together at the 
edges. In this way the different shades and colors are 
matched; this process requires much skill and time, particu¬ 
larly when valuable fur is being used and a perfect fit 
required. 

Furs vary in price according to kind and quality; gar¬ 
ments or other articles made of good fur are very expen¬ 
sive, some costing hundreds of dollars. 

The main supply of fur in this country is obtained from the 
Hudson Bay locality. Large quantities of fur are prepared 
and manufactured into wearing apparel, rugs, robes, etc., 
annually. The fur trade has become a leading and profit¬ 
able industry. 

Remarks on cost, uses, etc., of fur. 

& S 

DIAMOND. 

The diamond is the most precious of all stones next to 
the ruby, and the hardest of all known substances. Its 
property of hardness is so great that it will scratch or cut 
any other substance. 

It is composed of carbon, a simple elementary substance, 
crystallized, and in its greatest purity. Diamonds are 
generally clear and colorless like water, although some- 


THE TEACHER'S AID. 


67 


times, from the presence of some slight foreign intermixture, 
they are white, gray, yellow, green, brown and more rarely 
orange, red, blue and black. 

Its hardness renders it incapable of being cut or scratched 
by any other substance, and in cutting and polishing dia¬ 
monds, diamond dust is used. 

Its primary form is a regular octahedron, but it appears 
in rhomboids, and its crystals often have curved faces and 
edges. The estimation in which it is held as a precious 
stone is due to its remarkable hardness, rarety and brilli¬ 
ancy. Diamonds are used as articles of ornament, in jew¬ 
elry, etc. 

The art of cutting diamonds, although long practiced in 
India, was not known in Europe till after the middle of the 
fifteenth century. Previous to that time diamonds were 
set without being cut, and in that state they have often a 
rough, dull, uneven surface. 

Diamonds are not only found in the form of perfect crys¬ 
tals, but also in rolled grains, and they are obtained partly 
from alluvial soils and sands of rivers, and from rocks, 
chiefly of a quartzy-sandstone nature. 

Diamonds are cut into various forms, but principally 
into brilliants and rose diamonds. The brilliant cut is the 
more expensive stone, but it is this method of cutting and 
dressing that brings out the brilliancy and beauty of the 
stone; when cut this way, it has an octagonal face, sur¬ 
rounded by numerous facets; and the greater the number of 
facets, the greater the value of the stones. Lapidaries some¬ 
times multiply the number of facets in order to conceal little 
imperfections in the stones. 

Rose diamonds have a flat base surmounted by two 
rows of facets, the upper six of which unite in a point. 
The stones which are too thin to be cut into brilliants are 


68 


THE TEACHER'S AID. 


cut into rose diamonds. And stones which are extremely 
thin are cut into what are known as table diamonds. 

The value of diamonds is differently estimated. The 
rule generally adopted being to square the number of 
carats and then multiply it by the price of a single carat. 
The market value of diamonds varies according to the 
supply, and the demand for them made by the change in 
fashion. 

There is a way of imitating diamonds by joining a 
diamond as an upper part, on some other kind of a stone. 
There is also a process by which artificial diamonds are 
manufactured in such a state of perfection as to baffle any 
but experts in detecting them from the genuine diamonds. 

The best test for the genuine diamond is its hardness. 
The “paste” or imitation is always lighter in weight than 
the genuine. The small and inferior diamonds are called 
Bort, and command a ready sale for use in the arts. They 
are reduced by pounding in a steel mortar, and in this form 
are called diamond-dust, and are used by the lapidary for 
cutting, dressing and polishing the other and better dia¬ 
monds, all kinds of gems, and for the polishing and finishing 
of rock-crystal for the manufacture of spectacles. 

Minute fragments are used for drilling small holes in 
rubies and other hard stones employed in watch-making; 
for gold and silver wire-drawing; by glaziers for cutting 
glass, and for numerous other purposes. 

There are some particular diamonds which from their 
unusual size, or from some particular historical circum¬ 
stance, are of very great interest. 

The largest and most valuable collections of diamonds 
are in the possession of the various crowned heads of the 
world. 

Many localities in India are celebrated for the produc¬ 
tion of diamonds, Golconda in particular. Other noted 


THE TEACHER’S AID. 


69 


diamond regions are Brazil, the Ural Mountains, Algeria, 
South Africa, Australia, and some have been found in 
North Carolina and Georgia. 

Diamond mines usually consist of mere diggings and 
washings of alluvial soils, or deposits. In Brazil the method 
pursued is to rake the alluvial matter backward and for¬ 
ward on sloping planes, over which a stream of water is 
made to run, until the lighter substances are carried off; 
the larger diamonds are then collected by hand, and the 
remaining sediment carefully washed and examined for 
the smaller stones. 

The Kimberly Mines, one of the “dry diggings,” is 
about two hundred and fifty feet deep. Large numbers of 
workmen are employed in these mines and fields, but they 
are watched closely, and are usually very poorly paid for 
their time and labor. 

Note: Remarks on cost, uses, mines, fields, etc. 


CLAY. 

Clay is the name applied to certain substances which 
are mixtures of silex, alumine, and sometimes lime, mag¬ 
nesium, alkali and metallic oxides. 

It is a species of earths which are compact, hard and 
weighty when dry, but become stiff, pasty, viscid and 
ductile when moistened. It is smooth to the touch when 
moist; it readily mixes with water in all proportions, 
giving the water a murky appearance which does not 
readily subside. 

Most clays absorb moisture and become soft, pliable, 
tenacious and easily moulded into any shape. The purest 
kinds of clay are those which are obtained directly from 


70 


THE TEACHER'S AID. 


the decomposition of granite rock, which is considered the 
original source of clay. 

These granite rocks are mainly composed of feldspar, 
quartz and mica. Clays vary in purity according to the 
purity of the substances from which they are obtained. 

When in a state of purity, it cannot be consumed by 
water or fire, and retains its color and form, even when 
heated to redness. It contracts more or less on the appli¬ 
cation of heat, and when placed in water, after becoming 
cold, will absorb the water, but in no way does this affect 
the clay. 

When clay is freed from all impurities, it will stand the 
most intense furnace heat without melting, and for this 
reason it is well adapted for the manufacture of crucibles, 
fire-brick, and other things to which intense heat is to be 
applied. 

When mixed with impurities, it may be melted at a 
high temperature, in which case it forms a glaze. And in 
the manufacture of porcelain, delft, etc., other substances 
are mixed with the clay in order to produce this effect. 

In the manufacture of brick, the clay is mixed with 
sand in order to overcome its tendency to shrink. The 
most important and useful variety of clay is that known as 
china-clay, which is used for the manufacture of porcelain, 
etc. Potter’s clay is that variety which is used for the 
manufacture of earthenware articles. Common clay is 
used for the manufacture of brick, tile and all coarser clay 
articles. Pipe clay, and a variety of clay found in Europe, 
are used for the manufacture of pipes, and a light porous 
brick, which floats on water. 

The uses to which the various kinds of clays are applied, 
are numerous; the chief ones being in the manufacture of 
dishes, vases, urns, mortars, crucibles, brick, tile, and many 
other useful and ornamental articles. 


TIIE TEACHER’S AID. 


71 


Some of the very fine clays are quite expensive, and 
from these only the very finest of articles are made. Other 
clays are inexpensive, and from these cheaper grades the 
more common and coarser objects are manufactured. 

Note: Remarks on cost, uses, etc., of clay. 

PERFUMERY. 

Perfumery, or perfumes, are delicate fumes, or odors, 
which are derived from the Vegetable and Animal King¬ 
doms. Perfumes are of three distinct classes when de¬ 
rived from plants, and there is a fourth class, which is of 
animal origin. 

Class I. These are the most ancient, and have been in 
use from the earliest period of which there is record. 
They consist of the various gum-resins, which exude nat¬ 
urally from the trees which yield them; and in order to 
increase the product, the trees are often purposely wounded 
or cut. 

The most important are benzoin, olibanum, myrrh and 
camphor. Gum-resins form the chief ingredient in incense. 

Class II. To this class belong those perfumes which 
are procured by distillation. All odor-bearing plants con¬ 
tain a fragrant principle in minute glands or sacs; these 
are found sometimes in the rind of the fruit, as the lemon 
and orange; in others it is in the leaves, as sage, mint, 
and thyme; in the wood, as rose-wood and sandal-wood; 
in the bark, as cassia and cinnamon; in the seeds, as cara¬ 
way and nutmeg. 

These glands, or bags, of fragrance, may be plainly seen 
in a thin-cut stratum of orange peel; so also in a bay leaf, 
if it be held up to the sunlight, all the oil cells may be 
seen like specks. 


72 


THE TEACHER’S AID. 


All these fragrant-bearing substances yield, by distil- 
ation, an essential oil peculiar to each. The old name for 
these pure odoriferous principles was Quintessence. Lat¬ 
terly they have been termed essential oils. 

They are now, however, in modern scientific works often 
termed “ Ottos,” from the Turkish word ottar, which is 
applied to the well-known otto or attar of roses. 

All the various essential oils are slightly soluble in 
water, so that in the process of distillation the water which 
comes over is more or less fragrant. 

The process of distillation is very simple; the fragrant 
part of the plant is put into the still and covered with 
water; and when the water is made to boil, the ottar rises 
along with the steam, is condensed with it in the pipes and 
remains floating on the water, from which it is easily sep¬ 
arated by decanting. 

Every fragrant substance varies in the yield of essential 
oil. The variety of essential oils is endless. All these 
ottos are very soluble in alcohol, in fat, butter, and fixed 
oils. They also mix with soap, snuff, starch, chalk, 
sugar, and other bodies, to which they impart their 
fragrance. 

Class III. These are the perfumes proper, such as are 
used for perfuming handkerchiefs, etc. Contrary to the 
general belief, nearly all the perfumes derived from flowers 
are not made by distillation, but by the process of enfleur- 
age and incantation. 

The odor of flowers does not, as a general rule, exist in 
them as a store or in a gland, but is developed as an ex¬ 
halation. While the flower breathes it yields fragrance, 
but kill the flower and the fragrance ceases. 

In the location where these perfumes are obtained there 
are acres of jasmines, tuberoses, violets, roses, oranges, 


THE TEACHER’S AID. 


73 


acacia and other flowers; and when in blossom, the very 
air is laden with fragrance. 

Women and children gather the blossoms, wilich they 
place in little panniers like fishermen’s baskets hung over 
their shoulders. They are carried to the laboratory of 
flowers and weighed. 

In the laboratory the harvest of flow T ers has been antici¬ 
pated. During the previous winter great quantities of 
grease, lard, and beef-suet have been collected, melted, 
w r ashed and clarified. 

In each laboratory there are numerous sashes, or framed 
glasses, upon which the grease to be scented is spread, and 
upon this grease the flowers are sprinkled or laid. This 
sash is, in fact, a frame with a glass in it as near as possible 
like window-sash, only that the frame is two inches thick, 
so that when one sash is placed upon another there is a 
space of four inches between every two glasses, thus al¬ 
lowing space for blossoms. 

The flowers are changed every day, or every other day, 
as is convenient in regard to the general work of the lab¬ 
oratory, or the flowering of the plants. The same grease, 
however, remains so long as the particular flower being 
used yields blossoms. 

Each time fresh flowers are put on, the grease is worked 
—that is, stirred with a knife—so as to offer a fresh surface 
of grease to absorb the odor. The grease is at last scraped 
off, strained, and poured into canisters, and is now ready 
for the market. 

Fat or oil is perfumed with some flower by the process 
of maceration; that is, infusion of the flower with oil or 
melted fat. For this purpose purified fat is melted in a 
warm bath, and the fresh flowers are infused into it for 
several hours. Fresh flowers are then procured, the spent 



74 


THE TEACHER'S AID. 


flowers are strained away, and the new flowers added so 
long as they can be procured. 

In order now to procure the perfumes of these flowers 
in the form used for scenting handkerchiefs, etc., we have 
only to infuse the scented fat or oil, made by the above 
methods, in strong alcohol. 

Class IV. To this class belong all perfumes of animal 
origin, the principal ones of which are musk, civet, and 
castor. The aroma of musk is one of the most universally 
admired of perfumes. Civet is exceedingly potent as an 
odor, and when pure and smelled in the bulk, is almost 
unbearable from its nauseousness. Castor is at the present 
time almost obsolete as a perfume. 

The chief uses for perfumes are for the scenting of soaps, 
in the manufacture of toilet powders, in dentifrices, hair 
tonics, handkerchief perfumes, etc., etc. 

The cost of perfumeries varies, some being very ex¬ 
pensive, while others are very inexpensive. Some kinds 
are easily procured, while others are very difficult to 
obtain. 

Note: Remarks on cost, uses, manufacture, etc., of 

the various kinds of perfumery. 

& 

PENS. 

Pens are instruments designed for writing with fluid on 
paper, etc. In ancient times a kind of reed was used for 
this purpose, although sometimes the letters were painted 
with a fine hair pencil, as still done by the Chinese at the 
present time. 

The quill pen, made out of the coarse feathers or quills 
of birds, were in use from very early times, and so continued 


THE TEACHER’S AID. 


75 


till after the end of the first quarter of the nineteenth 
century, when the steel pens began to come into use. 

The quill pen was made by sharpening the quill on one 
side and splitting it in the center. The chief defect of the 
quill pen was its speedy impairment from use and the 
attendant trouble of frequently mending it; moreover, the 
most skillful maker could not insure uniformity of quality, 
and this variation affected the writer's work more or less. 

These defects led to the fitting of small metal or even 
ruby points to the nib of the quill pen; but as the fitting 
had to be made with great accuracy, very little success 
attended the experiment. 

At the beginning of the nineteenth century the manufact¬ 
ure of pens made of all metal was introduced. These metal 
pens consisted of a barrel of very thin steel, and were cut and 
split so as to resemble the quill pen as closely as possible. 

They were, however, very different, and, being dearer 
than the quill pens, they made very little headway in public 
favor or use. Their principal fault was hardness, which 
produced a disagreeable, scratching noise on the paper 
when writing. 

In 1820 Mr. Joseph Gillott, who dealt in the metal pens 
then manufactured, made an improvement which removed 
this great defect and gave a stimulus to the manufacture of 
steel pens which has since developed into an important 
industry. 

This new improvement consisted in making three splits 
instead of the single one formerly used. By this means 
much greater softness and flexibility were acquired. 

Mr. Gillott also introduced machinery for the carrying 
out of his invention, and thereby reduced the cost of pro¬ 
duction and consequently the cost of the finished pen, and 
as a result the use of the steel pen soon became universal, 
usurping almost wholly the place of the quill pen. 


76 


THE TEACHER'S AID. 


The cheaper grades of pens are made entirely by machin¬ 
ery, but the better ones require much hand labor for their 
completion. In the manufacture of pens, the steel is sent 
to the factory in sheets about eight feet long by three feet 
broad; this steel is prepared from the very best iron. 

The steel is prepared by dipping it for a short time in a 
dilution of sulphuric acid, which removes the scale or black 
surface. The acid is then completely removed by repeat¬ 
edly immersing the iron in clean water. 

The sheets of steel are then passed backward and for¬ 
ward through a rolling mill having smooth rollers, which 
reduces the steel to the exact thinness required and imparts 
to it greater compactness. It is next split into strips of 
various widths according to the kind of pen to be made. 

This is then passed through a cutting machine, which 
readily punches out pieces of the required shape for pens. 
These pieces or blanks are next taken through a succession 
of operations, each operation being conducted by a differ¬ 
ent person; women and girls are usually employed. 

The first process is called slitting; in this process the 
pieces are passed, one by one, into a cutting machine 
worked by a small hand-lever, which makes the two small 
side slits. 

The second process, which is called piercing, is per¬ 
formed by a similar machine or hand press, in which, how¬ 
ever, only one punch acts, and that cuts out the small hole. 

The repeated rolling and stamping of the metal has by 
this time made it hard and brittle, and it becomes neces¬ 
sary to anneal it. And in doing this, thousands of the slit 
and pierced blanks are put in an iron box and placed in the 
fire for a time, which softens them very much; this is the 
third process. 


THE TEACHER'S AID. 


77 


When cold, another workman receives them, and with 
another hand-press and a punch stamps or marks the 
name of the maker, which constitutes the fourth process. 

The fifth is somewhat similar and is sometimes omitted; 
it consists in placing the pieces under another press, which 
has a punch and die for embossing the pen with any orna¬ 
mental mark or design, trade-mark, etc. 

Up to this time the blank, which is still in the form of a 
flat piece of steel, is subjected to the sixth process, which 
consists in passing the pieces into another press, which has 
a sinker and grooved die. The flat blanks are passed 
under the sinker and pressed by the action of the lever into 
a groove, from which they come out with the edges curved 
up. 

The seventh process consists of hardening, which is done 
by placing the pens in an iron box or muffle and subjecting 
them to heat. When they have reached a red heat they 
are thrown into oil; this renders them exceedingly brittle 
and hard, too much so, in fact, for they have now to pass 
through the eighth or tempering process, which brings 
them to the required temper or hardness and elasticity. 

The ninth operation consists in scouring; this is done 
by putting a large number of the pieces mixed with sand 
and coarse emery into a tin cylinder which is kept revolv¬ 
ing by machinery; the friction of these materials with the 
pens themselves cleanses them from all impurities and 
brings out the natural color of the metal. 

The tenth and eleventh processes consist in grinding the 
outside of the nib, first lengthwise and then crosswise; this 
is done by different persons at different grinding-wheels. 

Next follows the most important operation, the twelfth 
process, which comprises the slitting , that is, making the 


78 


THE TEACHER'S AID. 


central or principal slit, upon the nicety and accuracy of 
which the whole value of the pen depends. 

This is done by a hand-press similar to the others, but 
the cutting part consists of two chisels, one fixed on a table, 
the other coming down on the depression of the lever; 
these chisels are so accurately adjusted as to just clear each 
other. 

The operator then holds the pens lengthwise on the 
fixed chisel and brings down the movable one so as to effect 
the beautifully clean cut which constitutes the most impor¬ 
tant feature in the manufacture of the pen. 

The thirteenth process consists in coloring the pens, 
which is done by heating them in a revolving cylinder over 
a charcoal stove, which gives them a blue or yellowish color 
according to the time they are subjected to the heat. 

The fourteenth or last process consists in giving them a 
coating of varnish composed of lac and naphtha. 

Besides the kind of pen especially described above, 
many other forms are made, especially the large and small 
barrel pens. But the processes for manufacturing the 
different kinds are about the same, or modifications of the 
process described. 

Gold pens are extensively manufactured, and as they 
resist the corrosive action of ink better than the steel pens, 
they are more durable. They are also much more expen¬ 
sive. 

Steel pens are more or less affected by the action of the 
inks in which they are dipped, and are liable to rust, par¬ 
ticularly in warm weather. This tendency to rust soon 
spoils the cheaper grades of steel pens. 

The manufacture of pens has become a very important 
industry and large quantities are made and used annually. 


THE TEACHER'S AID . 


79 


The metal pens have almost entirely usurped the place of 
the quill pen. 

Note: Remarks on the cost, uses, manufacture of 
pens. 

^ 

PUMICE. 

Pumice is a mineral found in volcanic regions. It is of 
a white or gray color, more rarely brown, yellow or black, 
and so full of vessels or cells that it is lighter than water, on 
which a mass of the substance will float. These vessels or 
cells are very often of an elongated shape. It is very hard 
and very brittle, and when reduced to a powder forms the 
pumice of commerce. 

It is much used for polishing wood, metals, glass, ivory, 
slate, lithographic stones, etc., and in the preparation of 
vellum, parchment and some kinds of leather. Among the 
other uses to which it is applied is the rubbing away of 
calosities and corns. 

Great quantities are exported from the Lipari Islands to 
all parts of Europe. In fact, the Lipari Islands are com¬ 
posed to a great extent of pumice, which occurs there, as in 
many other places, in the form of rock. 

Pumice is the chief product of some volcanic eruptions, 
although in some eruptions none is produced. There are 
three varieties of pumice, the glassy, the common and the 
porphyritic. It is hard, rough and very porous, and 
resembles the slag left in an iron furnace. 

Aside from being used as a scouring and polishing sub¬ 
stance, it is used with gasoline as a wash for cleaning fine 
textile fabrics, laces, ribbons, feathers, etc. 

Pumice, or powdered pumice stone, is very inexpensive. 

Note: Remarks on cost, uses, where obtained, etc. 


80 


THE TEACHER'S AID. 


TEA. 

The tea of commerce is derived from the dried leaves of 
a shrub which is a native of tropical countries. It consti¬ 
tutes one of the most important articles of commerce, and 
yields the most esteemed and extensively used of all non¬ 
alcoholic beverages. 

The Chinese tea shrub attains a height of from twenty 
to thirty feet, but in a state of cultivation only from five to 
six feet, with numerous branches and lanceolate leaves, 
which measure from two to six inches in length. 

The flowers grow singly, or two or three together, in the 
axils of the leaves; they are rather large, white and frag¬ 
rant, with five-parted calyx, six to nine petals and many 
stamens. 

The plant is considered sub-tropical, but bears a trop¬ 
ical climate very well, and can also accommodate itself to 
cold winters. In few of the countries into which it has 
been introduced, however, is the flavor of the dried leaves 
such as it is in China. 

The Chinese cultivate it chiefly on the southern slope of 
hills. A new plantation is made by sowing the seeds at 
proper distances, two or three seeds being put in a hole to 
secure a plant. 

The first crop is obtained in the third year, when the 
shrub is by no means full-grown. When about seven 
years old it yields but a scanty crop of hard leaves and is 
cut dowm, when new shoots rise from the root and bear 
fine leaves in abundance. This is repeated from time to 
time till the plant dies at the age of about thirty years. 

The tea farms are mostly in the north of China, and are 
usually of a small size and require much attention, for the 
plant will only thrive in well fertilized or very rich soil; 
and the spaces between the plants, which are four feet 


THE TEACHER'S AID. 


81 


apart, must be kept in good order and free from weeds. 
The farms always occupy the hill-sides, where the soil is 
deep and well drained. 

Although an evergreen, the leaves can only be gathered 
at certain seasons of the year, the first being in April, 
when the new leaves begin to burst from the buds; and 
some of these, in their most tender state, are gathered and 
made into young hyson of the finest quality. 

The ordinary picking begins just after the summer rains 
are over, at the beginning of May, and later in the season a 
third picking takes place, the product of which is inferior. 

The leaves, when freshly picked, possess nothing of the 
flavor or the odor of the dried leaves, these properties being 
developed by the roasting which the leaves undergo in the 
process of drying. 

Moreover, different qualities of tea are prepared from 
the same leaves, which may be made to yield black or green 
tea at will. 

In the process of drying, the leaves are roasted and 
scorched in such a way as necessarily produces many 
chemical changes in them, the result of such changes being 
to produce the varieties of flavor, ordor and taste by which 
the different kinds of teas are distinguished, and, second, 
that the different colors of black and green teas are due to 
the mode in which the leaves are treated. 

For green teas the leaves are roasted in pans almost as 
soon as they are gathered. After about five minutes of 
roasting, during which time they make a crackling noise, 
they become flaccid and give out a great deal of vapor; 
they are then placed on the rolling-table and rolled with 
the hands. 

They are then returned to the pans and kept in 

motion with the hands. In about an hour, or perhaps 

more, they are well dried, and their color, which is a 
6 


82 


THE TEACHER’S AID. 


dull green, but becomes brighter afterwards, has become 
fixed. 

The essential part of the operation is now over, nothing 
more being required than to sift and re-fire it. 

For black tea the leaves are allowed to spread out in the 
air for some time after they are gathered; they are then 
further tossed or shaken about until they become flaccid. 
They are next roasted for a few minutes and are then 
rolled, after which they are exposed to the air for a few 
hours in a soft and moist state; and, lastly, they are dried 
slowly over charcoal fires till the black color is fairly brought 
out. 

For the purpose of giving special scents to different 
varieties of tea, numerous odoriferous plants are employed 
in different parts of China. The Chinese give an artificial 
coloring to green teas sent to Europe, because it pleases the 
eye, but the coloring matter is very innocuous and is never 
produced by heating over copper plates—a popular error 
which had been persisted in for a long time without a 
shadow of truth for its foundation. 

Large quantities of tea are used annually in almost all 
parts of the world. The price of tea varies according to 
the kind and quality; it also varies in different localities 
according to the use and demand for it. 

Note: Remarks on cost, uses, cultivation, etc., of 
tea. 

& & 

TAR. 

The tar of commerce is obtained by the distillation of 
coal, wood and bone, each kind of tar being distinguished 
by the substance from which it was obtained, as coal-tar, 
wood-tar and bone-tar. Tar is a thick, viscid substance, 


THE TEACHER’S AID. 


83 


of a brownish color, or almost black, and has a strong 
aromatic flavor. 

The process of obtaining tar is very simple and applies 
alike to the different materials used. The coal, bone or 
wood to be used is placed in a funnel-shaped hole which is 
made in a bank. This hole is from six to eight feet wide at 
the top, and from one to two feet wide at the bottom. 

An iron pan is fitted at the bottom, and a long tube 
attached to this passes through the bank. Fire is then 
applied at the top, and it is then covered with twigs or peat. 

The material chars or burns downward from the top, 
and the tar, mixed with the other ingredients, collects in 
the pan at the bottom and is carried off through the pipe 
into a wooden vessel placed to receive it. From this vessel 
it is removed, freed from impurities and prepared for the 
market. 

Tar is extensively used in ship-building, as it is a protec¬ 
tion for wood, rope and canvas against the action of the 
wind and water. It is used to a limited extent in medicine 
and in the manufacture of artificial paving, gravel roofing, 
etc.; it forms an important part. It also forms a good 
coating for iron, to protect it from rusting. It is insoluble 
in water and highly inflammable. 

The distillation of coal-tar and wood-tar forms an impor¬ 
tant industry. Most of the wood-tar used is produced 
from the pine forests of North America and Europe. 

Bone-tar is used chiefly in the oiling of machinery. 
Coal-tar yields a very valuable dyeing material, which is 
extensively used in dyeing all kinds of fabrics. Some of 
the most brilliant and beautiful colors are produced by the 
dyes obtained from coal-tar. 

Remarks on cost, uses, value, manufacture, etc., of 
tar. 


84 


THE TEACHER'S AID. 


PEAT. 

Peat is a substance formed by the decomposition of 
plants amidst much moisture, and in marshes and morasses. 
The remains of the plants are often so well preserved in it 
that the species can easily be distinguished. 

Reeds, rushes and other aquatic plants may usually be 
traced in peat, and stems of heath are found in abundance; 
but it chiefly consists in the northern part of the world, of 
different species of bog-moss. 

Mosses of this genus grow in very wet situations, and 
throw new roots in their upper parts, while the lower parts 
are decaying and becoming converted into peat; and in this 
way shallow pools are often changed into bogs. 

It was at one time believed that bogs owed their origin 
to the destruction of forests, the fallen trees impeding the 
natural drainage and thus causing the growth of these 
marsh-plants, of which peat is formed. 

There are, however, satisfactory proofs that peat has 
accumulated in many places around trees. And firs have 
been found, in their natural position, to have six or seven 
feet of peat under their roots, although other trees, as oaks, 
are commonly found with their stumps resting on the soil 
beneath the peat. 

Yet it is not impossible that the destruction of forests, 
in some instances, by impeding the course of streams which 
flow through them, have caused the stagnation of water 
from which the growth of peat has resulted. Layers of 
trees are frequently found in peat, which seem to have been 
suddenly deposited in their horizontal position and some¬ 
times to be fallen by human hands. 

It is not improbable, however, that sometimes peat has 
been found where the soil has been exhausted by the long- 
continued growth of one kind of tree. 


THE TEACHER'S AID. 


85 


The growth of peat is often very rapid, bogs having been 
known to increase two inches in depth in a year. The 
surface of a bog sometimes becoming a floating mass of 
long interlaced fibres of plants known in Ireland as “old 
wives’ tow.” The vegetation on the surface is sometimes 
very green and compact, like a beautiful turf. 

Peat, therefore, is a vegetable matter, more or less 
decomposed by insensible degrees into lignite. The less 
perfectly decomposed peat is generally of a brown color; 
that which is more perfectly decomposed is nearly black. 

Most peat possesses a more or less powerful antiseptic 
property, which is attributed to the presence of gallic acid 
and tanin, and is manifest not only by the perfect preser¬ 
vation of ancient trees, leaves, fruit, etc., but sometimes of 
animal bodies. Thus in some instances human bodies have 
been found perfectly preserved in peat after the lapse of 
centuries. 

The formation of peat may be regarded as one of the 
most important geological changes now in evident progress. 
It takes place, however, only in the cold parts of the world. 
In warm regions the decay of vegetable substances is so 
rapid after life has ceased that peat cannot be formed. 

The surface covered by peat is very extensive in all the 
colder parts of the world, although in the southern hemi¬ 
sphere no moss seems to enter into its composition; and the 
South American peat is said to be formed of many plants. 
The surface covered by peat in England is considerable; it 
is greater in Scotland, and very great in Ireland. 

Mere peat is not good soil, even when sufficiently drained, 
but by the application of lime, marl, etc., is soon converted 
into good soil and yields excellent crops. A mixture of 
peat is often of benefit to soils otherwise poor. And for 
many shrubs no soil is so suitable as one composed to a 


86 


THE TEACHER'S AID. 


great extent of peat. And for this purpose peat is in much 
demand by gardeners in order to formulate a soil suitable 
for certain kinds of plants. 

Peat is extensively used for fuel. It is the ordinary fuel 
for the greater part of Ireland and is there almost always 
called “turf.” To procure peat for fuel, the part of the 
bog to be operated upon must first be partially dried by 
means of a wide, open ditch or drain. Its surface is then 
pared off with the spade, to the depth of about six inches, 
to remove the coarse, undecomposed vegetable matter; the 
peat is afterward cut out in pieces called “peats;” these 
peats are in the form of bricks and are cut by means of a 
peculiar implement called in Ireland a slane and in Scot¬ 
land a peat-spade. This tool resembles a long, narrow, 
sharp spade, the blade of which is furnished on one side 
with a tongue set at right angles to it. This imple¬ 
ment is used by the hands alone, without pressure of the 
foot.- 

When cut, the soft peats are removed to a convenient 
place where they are set up to dry. When sufficiently dry 
they are conveyed to the place where they are destined to 
be used, and are either piled in an outhouse or in the open 
air. And in this form they are ready for use. 

The operation of peat-cutting is always performed in 
Spring or Summer. In countries depending wholly, or 
almost so, on peat for fuel a very rainy season sometimes 
occasions great inconvenience and even distress by prevent¬ 
ing the cutting and drying of the peat. 

Peat is a light and bulky substance and cannot be con- 
veyed to any great distance without considerable expense. 
Efforts have, however, been made, both in Scotland and 
Ireland, to render it generally more useful, by compressing 


THE TEACHER’S AID. 


87 


it until its specific gravity is nearly equal to that of coal. 
If this could be done it would greatly aid in reclaiming the 
boggy lands in these countries. For this purpose it is first 
reduced to a pulp and then compressed. This compressing 
of peat has not been advantageously prosecuted on an 
extensive scale. 

Peat-charcoal, made from uncompressed peat, is very 
light and inflammable, and therefore unsuitable for many 
purposes, but for others it is particularly adapted, and no 
kind of charcoal excels it for antiseptic properties. 

It is an excellent fertilizer for many kinds of soil, and 
great crops have often been obtained by its use. Peat- 
charcoal is very highly esteemed for the smelting of iron 
and the working and tempering of the finer kinds of cutlery. 
Charcoal made from compressed peat is in density far 
superior to wood charcoal, and is capable of being used as 
coke. 

The Irish Amelioration Society some years ago encour¬ 
aged the conversion of peat into charcoal, but it seemed not 
to have paid as a commercial speculation, although the 
resulting charcoal was of a good quality. 

Various companies have been formed for the purpose of 
obtaining valuable products from the destructive distilla¬ 
tion of peat. But so far no product has been found suf¬ 
ficiently profitable to be manufactured. 

Flower-pots and other small articles of ornament are 
often made from peat, but its chief use is as an article of 
fuel. It is usually an inexpensive article in the countries 
where it is obtained. 

Note: Remarks on cost, uses, formation, etc., of 
peat. 


88 


THE TEACHER'S AID. 


OPIUM. 

Opium is the crystalline liquid that exudes from the 
capsule of the poppy, or, in other words, the dried juice of the 
unripe capsule of the poppy. It is derived from a species 
which is sometimes called the common and sometimes the 
white poppy. But all species of the poppy yield opium in 
some proportion. 

It is one of the most valuable of medicines, and acts as a 
stimulant, exhilirant and tonic according to the quantity 
used and the period for which it is used. 

The plant is probably a native of some of the warm parts 
of Asia, although it is now common in cultivated and waste 
grounds throughout all the south and middle of Europe, 
and is occasionally found in many other parts of the world. 

It is an annual, varying in height from one to six feet; 
the plant is erect, branched and of a shiny green color, with 
ovate-oblong sessil leaves; the stem and leaves generally 
smooth. The branches terminate by large flowers on long 
stalks, and the capsules roundish-ovate and smooth. 

The cultivation of the poppy for the production of 
opium is carried on in many parts of India, although the 
chief opium district is a large tract of land on the Ganges 
about six hundred miles in length and two hundred miles in 
breadth. The poppy is also extensively cultivated for 
opium in the Asiatic provinces of Turkey, in Egypt and in 
Persia. 

The purest extract is procured from the border of the 
Mediterranean sea. Europe and the United States obtain 
their supply from India and China. 

For its profitable cultivation the poppy requires a rich 
soil. The soil should be fine and rich when the seeds are 
sown. The subsequent cultivation consists chiefly in weed¬ 
ing and thinning. 


THE TEACHER'S AID. 


89 


Irrigation is profitably employed. Mild, moist weather 
is regarded as most favorable during the time for collecting 
the opium. Very dry weather diminishes the flow of the 
juice, and very much rain is injurious. 

After flowering, when the poppy heads are full-grown, 
the workmen take a little iron instrument, which is made 
of three or four small plates of iron, narrow at one end and 
wider at the other, which is also notched like a saw; with 
these instruments they wound every full-grown poppy 
head as they make their way through poppy fields. 

This operation is always performed in the morning, 
before the heat of the sun is felt; during the day the milky 
juice of the plant oozes out, and early the following morn¬ 
ing it is collected by scraping it off with a kind of scoop and 
placing it in an iron vessel, which hangs at the side of the 
gatherer. 

When this vessel is filled it is removed from the field and 
the contents transferred to a shallow, open brass dish, 
which is left for a time tilted on its side, so that any watery 
fluid may drain off; this watery fluid is very detrimental to 
the opium if allowed to remain in it. 

It now requires daily attention and has to be turned 
frequently so that the air may dry it equally until it acquires 
a certain solidity or hardness, which usually requires three 
or four weeks. 

It is then packed in small earthen jars and taken to the 
factories; here the contents of these jars are turned out and 
carefully weighed, tested and valued; these weights and 
values are then credited to the cultivator who produced the 
opium. 

The opium is then put into large vats which hold the 
crop produced by whole districts, and the mass is kneaded 
thoroughly and then made into balls or cakes for the mar¬ 
ket. 


90 


THE TEACHER'S AID. 


This operation, which is a very important one, is con¬ 
ducted in long rooms or sheds; the workmen sit in rows and 
are closely watched by the overseers, to make sure that the 
work is properly done. 

Placed before each workman is a tray, and within easy 
reach is placed a tin vessel which holds as much opium as 
will make from three to five balls. On the tray is another 
basin containing water and a small tray. 

On this small tray stands a brass cup, in which the balls 
or cakes are molded; also a supply of thin layers of poppy 
petals, formed by laying them out, overlapping one another. 
These petals are prepared by women in the poppy-fields 
and placed on the tray; with these leaves or petals is a cup 
filled with a sticky fluid called lewah, which is procured 
from opium of an inferior quality. 

In forming the balls or cakes, the operator begins by 
taking the brass cup and placing on its bottom one of the 
cakes of poppy petals which he has coated over with the 
lewah; he then adds other cakes of the petals to overlap the 
first and adhere to it until the cup is lined throughout, and 
a covering is thus formed for the opium which is to be 
molded in the cup. He next takes the exact quantity, or 
as near as he can guess, and works it into a ball, and then 
places it in the cup, so that the petals which line the cup 
will enclose and adhere to it. Other petals are placed on 
top and the whole gathered round the ball, forming a cov¬ 
ering about as thick as a bank-note. 

It is then taken to a large drying-room, where the balls 
are placed in tiers on lattice-work frames. They are fre¬ 
quently turned and examined by boys to keep them free 
from insects and other injuries. When thoroughly dried, 
these balls are packed in chests for the market. 

Prepared opium (smoking opium) is properly an extract 


THE TEACHER'S AID. 


91 


prepared by subjecting the crude gum to a thorough filtra¬ 
tion with water assisted by heat. In China, where the 
prepared opium is extensively used, the process is conducted 
with the most scrupulous care and exactness. 

Opium is combined in various ways with other narcotics. 
It is smoked by the Chinese, and the habit is also acquired 
by people in many parts of the world. It is a very injuri¬ 
ous habit, and one which seems very hard to overcome. 
Its narcotic influence places people who use it in a state of 
stupefaction. 

The import duties on this drug are placed so very high 
that attempts are made to smuggle it into the countries to 
which it is exported. Many ingenious methods are con¬ 
trived to smuggle it in free of duty, and the customs officers 
have to exert great watchfulness in examining all goods 
imported from the countries that produce opium, in order to 
see that no opium is smuggled in with the other goods. 

The drug is frequently packed in the shells of a Chinese 
nut which is very similar to our walnut, and is sent to 
America and other countries in this shape. The custom 
house officials who examine these goods do not open all 
these nuts; but whenever they see nuts which they have 
reason to believe are aiding the smugglers they crack the 
nuts to ascertain. 

Note: Remarks on uses, cost, production, importation, 
smuggling, etc. 


PLUMBAGO. 

Plumbago, graphite or black lead is a mineral consisting 
chiefly of carbon and a small portion of iron, alumina, silica, 
lime, etc., mixed with it, in varying proportions. 


92 


THE TEACHER'S AID. 


Black lead is the most popular name, and that by which 
it is known in the arts; this name seems to be erroneously 
applied, however, as no lead appears in its composition. 
The name was probably given on account of its resem¬ 
blance to lead. The name graphite is generally preferred 
by mineralogists. 

Plumbago occurs in the native state in hexagonal 
prisms, generally massive, and more or less compact, scaly 
and radiated. 

Its color is grayish-black, and it has a slight metallic 
lustre; it is dense and opaque. It is a perfect conductor of 
electricity. When touched with the fingers it gives the 
impression that it is greasy. Next to the diamond it is the 
purest form of carbon. 

Plumbago is incombustible, and for this reason it is used 
in the powdered form, mixed with half its weight of clay, in 
the manufacture of crucibles or melting pots which have to 
be subjected to the application of intense heat. 

It is extensively employed as a dressing or polish for 
iron railings, grates, stoves, etc., in order to give them a 
black, glossy appearance; it is used on belts and other parts 
of machinery to reduce friction, and is used in lubricat¬ 
ing, as a substitute for lard, tallow, oils, etc. 

A very important use to which graphite is applied is in 
the manufacture of lead pencils; and for this purpose alone 
large quantities are consumed annually. 

Siberia furnishes graphite in abundance, and England 
has a limited supply. Canada and the United States fur¬ 
nish a goodly supply of this mineral. 

Remarks on cost, uses, etc., of plumbago. 


THE TEACHER’S AID. 


93 


PETROLEUM. 

Petroleum, or native naphtha, is an inflammable oil or 
liquid which exudes from the earth in certain localities and 
collects on the surface of wells and ponds; it is sometimes 
found oozing from cavities in rocks. 

For commercial purposes it is generally obtained by 
sinking deep wells where the petroleum is known to exist, 
and drawing the oil off. The essential ingredients of 
petroleum are carbon and hydrogen. 

Native naphtha or petroleum, sometimes called rock-oil, 
is found in North America, France, Japan, Persia, Burmah, 
Italy, Siberia and along the shores of the Caspian sea. 

In its native state it varies in degrees of consistency 
from a thin, light, colorless fluid, which occurs in some 
localities, to a substance as dense as butter and nearly as 
heavy as water. But the various kinds, when rectified, 
have almost the same consistency; they all contain carbon 
and hydrogen, but no oxygen. 

Rectified or refined petroleum is a thin, oily fluid of a 
watery-bluish color when pure, and of a yellowish color 
when not well purified. It is highly inflammable, and will 
ignite readily when brought in close contact with light, and 
for this reason great care must be used while handling it. 

Prior to the discovery of the oil fields in Pennsylvania 
the Burmese petroleum, or rock-oil, was one of the best 
known and most extensively used oils. 

The discovery of the oil fields of Pennsylvania was one 
of the greatest wonders of the century and also a great 
source of wealth and industry. 

The principal oil fields of the United States are in Penn¬ 
sylvania, West Virginia, Ohio and Kentucky; but the 
supply of Pennsylvania is estimated at six or seven times 
as great as all the others combined. 


94 


THE TEACHER’S AID. 


The oil regions of the United States cover an area of 
over one hundred miles in length by from thirty to fifty 
miles in width, and the supply is supposed to be inexhaust¬ 
ible. 

The origin of these great deposits of petroleum has been 
a source of wonder and much scientific research. Geolo¬ 
gists in general believe it to be produced by the decompo¬ 
sition of both vegetable and animal matter. 

Soon after the discovery of oil in this country, wells were 
bored from which the oil was drawn off. The first well was 
made in 1859, and during that year three million five hun¬ 
dred thousand gallons of oil were obtained. The wells 
which have been made since then are almost numberless, 
and many of them are sunk to the depth of several hundred 
feet. 

The output of petroleum has steadily increased from 
year to year until at the present time the petroleum trade 
of the United States employs thousands of laborers and 
utilizes large quantities of machinery. 

Petroleum has been used in lamps for illuminating pur¬ 
poses from very early times in Japan and Persia, and for at 
least a century past in Italy. 

Petroleum is very inflammable, and explosions often 
occur from its use, causing fearful accidents which are 
usually attended with loss of life and property. The 
imperfectly refined oils are more liable to explode than the 
perfectly refined, or pure, oils. 

The chief use to which petroleum has been applied is for 
illuminating purposes; but it is also used to a certain extent 
for lubricating machinery, etc. 

The price of this oil varies according to the quality, 
which is usually determined by the degree to which it has 


THE TEACHER’S AID. 


95 


been refined, from five to thirty cents per gallon being the 
usual range in price. 

The United States produces large quantities of petro¬ 
leum annually, much of which is exported to other countries. 

Remarks on cost, uses, etc., of petroleum. 

CASTOR OIL. 

Castor oil is the product obtained from the seeds or 
beans of the castor oil plant. 

This plant is a native of the West Indies and South Asia, 
but it has been naturalized by cultivation in the southern 
part of Europe, America and other warm regions. 

In warm climates it is a perennial and attains a height 
of from twenty to thirty feet in one season’s growth. 

In the middle and even in the northern parts of North 
America it is planted in gardens as an ornamental shrub; 
in these localities it attains a much smaller growth than in 
the warm countries, or from three to ten feet in height. 

The flowers, which are produced late in Summer, grow 
in long racemes, which continue to grow and send forth 
new flowers at the upper end, while the flowers at the lower 
end of the stalk mature and are converted into the ripe 
capsule or seed-pod. 

Thus on one raceme may often be seen the blooming 
flower, the ripe and the partially ripe seed-pods. These 
racemes attain a length of from six to twelve inches and 
contain many capsules; the capsules, when young, are 
green, but as they develop in size and mature they become 
reddish, brownish-red and sometimes a bright red; when 
ripe they are usually of a dull brown or grayish color. 

The leaves are peltate and palmately clef ted, having 
from seven to nine clefts; they attain a width of from six 


96 


THE TEACHER'S AID. 


inches to two feet. They are dark green, tinged with 
purple, and are very beautiful. 

The castor oil plant is used for ornamental purposes on 
lawns and gardens, but the chief use is for the production 
of castor oil, for which it is largely cultivated. 

The castor oil is obtained from the beans either by 
means of expression or decoction, that obtained by decoc¬ 
tion being considered the better, as it is freer from impurities 
in the form of acid and mucilaginous matter which becomes 
mixed with it by expression; it is also less liable to become 
rancid than oil which is expressed. 

In order to obtain the oil, the beans are first separated 
from the capsules and then bruised by being passed between 
heavy rollers. 

If the oil is to be expressed, the bruised seeds are then 
subjected to heavy pressure under a hydraulic or screw 
press; but if the oil is to be decocted, the seeds are sub¬ 
jected to the action of heat and water. 

When castor oil is pure it is of a light yellow color; but 
when impurities are present it is of a greenish or brownish 
hue. The action of the sun tends to bleach castor oil, and 
for this reason the impure oils are exposed to the sun’s rays 
in order to make it appear pure. 

Castor oil has a very nauseous smell and an acrid, dis¬ 
agreeable, sickening taste, which may be overcome to a 
certain extent by the use of a small quantity of magnesia. 
It is often subjected to adulterations by the use of many of 
the fixed oils. 

This oil is used medicinally, being considered one of the 
best laxatives, the chief drawback being its disagreeable 
taste and the sickness which it often causes. It is some¬ 
times taken in coffee, which is thought to overcome its 
nauseating effects. 


THE TEACHER’S AID. 


97 


Large quantities of castor oil are produced and consumed 
annually in this country. As a lubricant it has few equals. 

Remarks on cost, uses, production, etc., of castor oil. 

^ & 

MICA. 

Mica is a mineral which consists principally of silicate of 
alumina combined with small proportions of silicate of 
potash, litharge, soda, oxide of iron and oxide of manga¬ 
nese. 

Owing to these admixtures and the varying external 
characteristics, numerous species have been designated by 
mineralogists. 

Mica occurs in masses, and can be readily split into 
sheets and also in beautiful crystals which are generally 
rhombic or six-sided. It is bountifully distributed over 
the earth’s surface. 

Common mica, also known as potash mica, contains a 
variable amount of silicate of potash and a small proportion 
of fluorine. It has a strong and often metallic lustre. 

Mica is colorless or of some shade of light-brown, gray- 
brown, black and sometimes violet or green; it is more or 
less transparent. Three or four distinctly different species 
of mica are known; they are unlike in composition and 
crystalline form. 

Mica is one of the essential elements m the composition 
of granite, gniess and mica slate. It is noted for the readi¬ 
ness with which it splits into thin, elastic plates; these 
plates are generally transparent or semi-transparent. 

The thinness and elasticity of these plates is remarkable; 
these qualities readily enabling it to be distinguished from 
talc and gypsum, which it very much resembles. The 

7 


98 


THE TEACHER'S AID. 


thickness into which the plates of mica are sometimes split 
does not exceed one three-thousandth part of an inch, and 
when split so fine the plates are quite transparent and are 
used in setting objects for the microscope. 

Large plates of mica, often a yard in diameter, are found 
in Norway, Sweden, Peru and Mexico; in these countries 
they are used as substitutes for glass in windows, etc. 

In this country, as well as in many others, mica is used 
as a substitute for glass in lanterns, as it can stand the 
change from cold to hot, and the reverse, much better than 
glass can. 

Mica is used in the construction of windows in war-ships, 
because it will not break like glass upon the discharge of 
cannon. It is used in the doors and sides of stoves for the 
purpose of permitting the light to shine through and thereby 
giving the stove a pretty and cheerful appearance. It is 
not affected by either heat or cold. 

It is used on the walls and ceilings of rooms to give them 
a brilliant appearance, and in the form of sand to sprinkle 
over writing. 

When mica is reduced to a very fine powder it is known 
as cat’s gold or cat’s silver, according to the color. 

Besides the common mica as above described, the fol¬ 
lowing may be mentioned: Lithia mica or lepidolite, 
which contains lithia in small proportions; this variety is 
often of a rose color or a peach-blossom color, and is used 
for ornamental purposes. It is found in many parts of 
Great Britain. 

Another variety, known as magnesia mica or biotite, 
contains about as much magnesia as alumina; it is often of 
a dark green color. Mica is a very useful mineral and is 
not very expensive, even when prepared in plates or sheets 
ready for use. 

Remarks on cost, uses, etc., of mica. 


THE TEACHER'S AID. 


99 


MUSHROOM. 

Mushroom is the name applied to certain plants of the 
fungi order. There are many different kinds, some of which 
are edible and used as food, while others are poisonous. 
The mushroom is the most valued species of fungi. 

The common mushroom is the most valued; it is a native 
of most of the temperate regions of both the northern and 
southern hemispheres. 

A very large, fine specimen of the common mushroom is 
found in Eastern Australia. It is of a regular convex shape 
when young, but becomes almost flat when old; it is fleshy 
and dry. It is white in color, with a tinge of brown or yel¬ 
low. The upper surface is usually smooth, never warty, 
but sometimes scaly; the under side is composed of thin, 
flat gills of unequal size, which are of a pinkish color when 
young, but change to dark brown as the plant becomes 
older. 

The pileus, or top, is attached at the center to the top of 
the stem, which is of a fine, fleshy texture. Toward the top 
of the stem there is a more or less distinctly marked mem¬ 
braneous ring. 

The mushroom thrives best in rich, damp, fertile soil, 
and the rapidity with which it springs up and matures is 
remarkable. For table use and for the making of mush¬ 
room ketchup, the young, undeveloped plant is preferred. 

There is a variety of fungi known as St. George’s agaric, 
sometimes called white caps, which is often sold in the 
market for mushrooms. These fungi grow in moist pas¬ 
tures and near old buildings, but they can readily be dis¬ 
tinguished from the common mushroom, as they are much 
larger and coarser and have a disagreeable smell; the gills 
are much lighter-colored, and when the flesh is bruised it 
L.ofC. 


100 


THE TEACHER'S AID. 


becomes yellow. These fungi sometimes attain a breadth 
of eighteen inches. 

It is a frequent occurrence for inexperienced persons to 
mistake the poisonous agarious phalloids, or toadstools, 
for the common mushroom, as they are very similar in 
appearance and are easily mistaken for one another by 
persons not thoroughly familiar with fungi. 

But when one is familiar with the properties of each, it 
is an easy matter to distinguish them. The toadstool 
has the ring at the bottom of the stem, the upper surface 
has warts or rough spots, and the gills on the under side are 
white, and it possesses a powerful smell, which becomes 
more disagreeable as the plant matures. 

There is another variety of mushroom much valued for 
table use; it is known as the fairy ring, and sometimes called 
Scotch bonnets. It springs up in the form of rings and 
circles, and is much smaller than the common mushroom, 
the pilus or top being seldom more than an inch in width. 
The stem is solid, fibrous and tough, and much longer in 
proportion than that of the common mushroom; it has'no 
ring at either top or bottom. The pilus is smooth, tough, 
fleshy, convex and of a watery-brown color; the flesh is 
white, and the odor strong and agreeable. 

The fairy ring is used like the common mushroom for 
soups and ketchups; it is also dried and powdered'and used 
as a flavoring for soups, sauces, etc. Besides the ones 
mentioned, there are many other edible species of mush¬ 
room. The common mushroom is very profitably culti¬ 
vated in the open garden, in cellars, sheds and houses. 

For garden cultivation the beds or ridges are prepared 
from earth and manure which is partly fresh and partly 
from some old hotbed. When grown in the house, boxes 
are filled with alternate layers of fine mould, straw and 


THE TEACHER'S AID. 


101 


manure. And when grown in cellars the methods em¬ 
ployed are very similar to the above. 

Different growers, however, modify these methods to a 
certain extent, the results being about the same. 

When the beds or boxes to be used are prepared the 
mushroom spawn is planted; this spawn is either collected 
from places where mushrooms grow or produced by arti¬ 
ficial means. In some cases the beds are prepared and the 
production of the mushroom left to chance, which is almost 
a certainty, as the spawn or spore usually exists in heaps of 
heated and fermented manure, straw, etc., and is almost a 
certain spontaneous production. And an abundant crop 
is usually the result. 

In the localities where mushrooms grow they are easily 
obtained, as the gathering of them is not difficult; for this 
reason they are quite inexpensive. But in large cities and 
places where they do not naturally spring into existence 
they are considered a luxury and are very costly. 

Remarks on uses, growth, cost, etc., of the mushroom. 

& & j* 

GINGER. 

Ginger is a product obtained from the plant known as 
zingiber officinale; it is a native of Gingi and China. There 
are other varieties found in the East Indies, West Indies 
and North America. 

These plants are perennial, herbaceous, with annual 
stems and creeping root-stalks. The stems are reed-like 
and invested with a smooth sheath of green, and attain a 
height of from three to four feet. The leaves, which are 
linear-lanceolate and smooth, grow in two opposite rows on 
the stem. The flowers are white, streaked with purple, 
and grow in compact spikes on short, leafless stems. The 


102 


THE TEACHER'S AID. 


root-stalk is about as thick as a man’s finger; it is knotty, 
fibrous and jointed. It is fleshy when fresh, but when dry 
becomes very hard. 

A native plant of North America, known as Indian or 
wild ginger, is sometimes used as a substitute for true 
ginger. 

The cultivation of ginger is quite easy and is carried on 
extensively in countries where the climate is suitable. In 
India it is cultivated in moist localities at an elevation of 
from four thousand to five thousand feet, on the Himalaya 
mountains. 

In the preparation of ginger for the market, the roots are 
dug when the stems of the plant have withered. They are 
washed clean and plunged into scalding or boiling water in 
order to kill or destroy the life in them. They are then 
either dried in this form or scraped, washed and dried. 

When dried in the root shape, the product obtained is 
known as black ginger, but the darkest shade of black 
ginger is only a stone color. When ground and dried, the 
product is known as white ginger; this is not in reality 
white, being only in light shades, except when bleached by 
the use of chloride of lime. 

The bleaching process is often employed in order to im¬ 
prove the appearance of the ginger; but it is not considered 
necessary or advisable. 

There is considerable difference in the original color of 
the root-stalk of ginger produced in different localities; this 
is chiefly due to the different varieties of the plant. 

Ginger is used medicinally as a stimulant, tonic and 
carminative. And for domestic purposes it is used as a 
flavoring or condiment. 

The qualities for which ginger is valued depend wholly 
on a pale, volatile oil which it contains; it is known as oil 
of ginger and is much lighter than water. 


THE TEACHER’S AID. 


103 


A delicious sweetmeat is prepared from the young root- 
stock. This is done by preserving the root in sugar; the 
product thus obtained is very highly esteemed in China, the 
East Indies and the West Indies. It forms an important 
export from these countries. 

The common ginger of commerce is of a yellow, light- 
yellow or grayish color, with a hot, burning taste and strong 
aromatic smell. 

The use of ginger was known to the Romans. It was 
valued in England as a medicine before the end of the 
seventeenth century. It is an inexpensive article, and 
large quantities are produced and consumed annually. 

Remarks on cost, uses, etc. 

jt 

GUNPOWDER. 

Gunpowder is an explosive made of saltpetre (nitre), 
sulphur and charcoal. These ingredients are mixed and 
reduced to a powder, granulated and then dried. 

In the manufacture of gunpowder great care should be 
taken to secure absolute purity in all the ingredients used. 
The most common impurity in saltpetre is common salt, 
which has a strong tendency to absorb atmospheric moist¬ 
ure, which has a weakening and injurious effect on the 
powder; therefore the salt must be separated from the 
saltpetre. 

Sulphur is freed from its impurities either by fusion or 
distillation. But the preparation and the quality of the 
charcoal used is the most important point. 

The charcoal should be as light and porous as possible, 
should yield a small amount of ash, and contain as little 
moisture as possible. The woods which yield the best 


104 


THE TEACHER’S AID. 


charcoal for gunpowder are black alder, poplar, spindle- 
tree, willow, dogwood and a few others. 

Many experiments have been made in order to deter¬ 
mine the proper proportion of ingredients to be used in 
order to produce the best powder. These experiments have 
had an almost universal result. 

In the manufacture of gunpowder the three ingredients 
to be used are reduced in separate mills to impalpable 
powders. These powders are then taken to the mixing 
house, where they are carefully weighed out into their 
respective proportions. The charcoal is next spread in a 
trough and the sulphur and saltpetre sifted upon it, and 
the mass partially mixed by hand. 

This mixture is then removed to the powder mill, where 
it is ground between millstones and thoroughly mixed in a 
wet state. This part of the process is so very dangerous 
that manufacturers are forbidden to grind very large 
quantities at a time. 

In order to prevent friction, which might cause ignition 
at this stage of the operation, all the bearings of the machin¬ 
ery are made of copper. 

The length of time employed in grinding depends on the 
quality of the powder to be produced; the time varies from 
one to six hours, and in the government factories the period 
is three hours. 

The mixture, which has become completely pulverized 
and caked by the moisture and pressure, passes from the 
mill in the form of small lumps called mill-cake; this cake 
is spread in layers three inches in depth, between copper 
plates, and intense pressure applied either by the use of 
screw presses or hydraulic engine pressure. 

When this operation is completed it is followed by the 
graining process, which is accomplished by forcing the 


THE TEACHER'S AID. 


105 


mill-cake through small holes made in a circular parchment 
seive, which is kept in rapid motion. 

The grains thus formed are of different sizes; and as 
uniformity in size is very essential, the grains are sifted 
through sieves of different degrees of fineness, beginning 
with the largest ones, which retain the largest grains of a 
uniform size; each successive sieve does the same, and in 
this way the sizes are separated and usually named 
according to their size. 

Pebble powder, which is as large and sometimes larger 
than hazel nuts, is made for use in modern cannon; the size 
of the different varieties diminishes from this to the very 
small, fine grains, which are used for fire-arms. 

Good gunpowder should be perfectly uniform in texture 
and in the size of the grains, which should be hard and 
smooth. Powder can be ignited by any burning substance, 
by red-hot metal, by an electric spark and by concussion. 

The manufacture of gunpowder is very dangerous, and 
great care must be taken to protect it from fire, heat or 
sudden jars or shocks. Working in gunpowder factories is 
a very unhealthy occupation. 

Gunpowder, when complete, is composed of grains of 
various sizes, with a hard, smooth, shiny surface and of a 
grayish color, in which form it is known as the gunpowder 
of commerce. 

It is packed in kegs or barrels and stored in cool, dry 
places, where it is designed to be kept free from moisture, 
heat and concussion. 

Its chief uses are in artillery for war and military pur¬ 
poses; by the miner for blasting coal and rock; in blasting 
earth in making excavations for building and other pur¬ 
poses, and by the sportsman in shooting game. 


106 


THE TEACHER'S AID. 


The prices of gunpowder vary according to the kind and 
quality. Large quantities of gunpowder are manufactured 
and consumed annually. Its manufacture forms a very 
important and useful industry, and one which is carried on 
largely in almost all countries. 

Note: Remarks on cost, uses, manufacture, etc., of 
gunpowder. 


& 

HOMINY. 

Hominy is maize, or Indian corn, when hulled and 
broken into coarse particles. The hulls are removed by 
boiling the grains of corn in water, to which has been added 
a quantity of common lye. 

The action of the heat, water and lye loosens and 
removes the hulls, which are then separated from the grain 
by the use of large quantities of cold water. This washing 
process also removes all traces of the lye and leaves the 
hulled grain white, smooth and pure. 

The grains are next subjected to a process whereby they 
are broken into irregular particles. And when this process 
is completed they constitute a mass of hard, white, flinty 
grains known as the hominy of commerce. 

Hominy is prepared as a food by being boiled in water 
and seasoned with salt, pepper, sugar, etc., according to 
taste. It is a very healthy and inexpensive food, of which 
large quantities are used annually. It is a product of all 
corn-growing countries. 

Remarks on cost, uses, production, etc., of hominy. 


THE TEACHER'S AID. 


107 


BAMBOO. 

The bamboo is a plant of the reed kind; it is a product of 
the East Indies, the West Indies, China and in some other 
warm climates of both eastern and western hemispheres. 
The cultivation of the bamboo has been tried in England 
and has proven fairly satisfactory. 

There are many different species of bamboo, all of which 
are of great importance to the inhabitants of the countries 
in which they are found. 

The species vary in height from the very small ones to 
those of the tree form, which attain a height of from twenty 
to sixty, and in extreme cases from seventy to one hundred 
feet. The stems are hollow, except at the joints, which are 
solid; the interior of the hollow part contains a soft, white, 
spongy pith. The stems have a shiny appearance as if 
they were varnished. 

The stem is generally straight and slender, varying in 
thickness from an inch or two in diameter in the smaller 
species, all the way up to eighteen inches in the larger ones. 
The joints vary also in length according to the length of the 
plant; in the larger ones a length of several feet is some¬ 
times attained. 

All varieties of bamboo have a jointed, subterranean 
rooi>stalk, which sends forth shoots varying in number 
from ten to one hundred. The bamboo grows very rap¬ 
idly, attaining its full height in a few months. The joints, 
which are hollow, except for the pith in the center and the 
solid portion where they are connected, are furnished with 
one or two sharp spines. 

The stem grows to its full height without branches, but 
at the top throws out straight, horizontal branches, which 
form a dense mass. Many of them are furnished with 
sharp spines, which present a formidable appearance. For 


108 


THE TEACHER’S AID. 


this reason they are often planted to form a hedge, which 
makes a strong barrier of defense even against armed 
troops. 

The leaves are oval in shape and eight or ten inches in 
length. The flowers grow in large panicles and spring 
from the joints of the stalks 

Almost all parts of the plant are made practical use of. 
The soft, juicy shoots, when quite young, are used as a 
food, like asparagus, and, like that plant, they are covered 
with earth or protected in trenches to keep them fit for use 
as long as possible. 

By removing the pith from the joints and leaving one end 
closed, they are converted into vessels for holding water 
and other fluids. And when the solid portions of the joints 
are removed they serve as water-pipes. The larger ones 
are used for building purposes, for houses, bridges, etc. 

The smaller ones serve as canes and walking-sticks, and 
the very small ones are used for the stems of pipes and for 
making wicker-work. The inner parts of some kinds are 
used by the Chinese for manufacturing paper. 

The leaves of some kinds are used for thatching pur¬ 
poses, while others are braided and made into hats by the 
Chinese. The seeds of some varieties are used in the manu¬ 
facture of a kind of beer used in those countries. 

The bamboo is cultivated with great care in regular 
plantations. The plant is propagated by means of shoots 
or suckers, which are placed in pits eighteen inches to two 
feet apart. The setting of the shoots is done at the close of 
Autumn or the beginning of Winter. 

Note: Remarks on uses, etc., of the bamboo. 


THE TEACHER’S AID. 


109 


ALCOHOL. 

Alcohol is a pure or highly rectified spirit obtained from 
fermented liquors by the process of distillation. It is a 
limpid, colorless liquid of a pungent taste and a slight 
agreeable odor. It is the characteristic ingredient of all 
fermented beverages, to which it imparts their intoxicating 
properties. 

Owing to its application in the production of liquors and 
its use for other purposes, it is considered one of the most 
important substances produced by art. 

There is only one true source of alcohol, namely, the 
fermentation of sugar or other saccharine matter. Sugar 
is a product of the vegetable kingdom and is found in some 
proportion in some part of most plants. It occurs free in 
some plants, while others contain starch which can be con¬ 
verted into sugar. 

The most suitable vegetable substances for the produc¬ 
tion of alcohol are those which contain the greatest supply 
of sugar or starch. 

Owing to the attraction which alcohol and water have 
for each other, it is impossible to produce pure alcohol by 
distillation alone. The common spirits such as whisky 
and brandy are about half water and half alcohol. The 
very highest concentration possible to be obtained by dis¬ 
tillation yields ninety per cent of alcohol and ten per cent 
of water. 

Alcohol is used medicinally, both internally and exter¬ 
nally, the form most common for internal use being brandy, 
and is that which is recommended by physicians. 

In case of indigestion and sea-sickness it is used as a 
stimulant, and in cases of fever and wasting diseases it is 
used as a restorative. It acts as an excitant and is also 
applied to stop hemorrhages. 


110 


THE TEACHER'S AID. 


It is not affected by cold and is non-freezable at any 
degree of temperature. This property has led to the use of 
alcohol in the manufacture of thermometers intended for 
use in arctic countries; and for this purpose the alcohol 
used is colored red by the use of cochineal. 

It is highly inflammable. It is much employed in the 
arts and in pharmacy. It is a powerful solvent and is used 
for dissolving the various gums, resins and oils, for which 
reason it is largely used in the preparation of varnishes. 

Alcohol, when used in a concentrated form or to excess, 
exerts an irritating and poisonous action on the membranes 
and animal tissue. And when used to excess its action on 
the animal tissue produces the state known as “ drunken¬ 
ness.” 

When taken in moderate doses it is termed a stimulant; 
but when used in excess it is termed an intoxicant. As a 
stimulant, alcohol excites both mental and bodily powers 
beyond their ordinary action, and after the effects have 
passed off there is a general feeling of reaction. 

Used as an intoxicant, both mental and physical powers 
are impaired, and when the use of this intoxicant is con¬ 
tinued until it becomes a habit these powers become per¬ 
manently injured. 

Alcohol ingites readily and burns with a bright flame; it 
is used as a fuel in the spirit lamp. 

There are different grades of alcohol, owing to the dif¬ 
ferent degrees of purity attained. The market price varies 
according to purity, and in the better grades attains a very 
high price. 

Note: Remarks on the cost, uses, manufacture, etc., 
of alcohol. 


THE TEACHER’S AID. 


Ill 


CEMENT. 

Cement is the term applied to any glutinous or other 
substance that has the property of uniting, by its inter¬ 
position, other bodies or substances in such close adhesion 
that they will remain so. 

This adhesion may result from chemical or from mechan¬ 
ical action, and be due to the adhesive properties of the 
cements by which the air is excluded from the surface of 
the objects united. 

Mortar, glue, solder, etc., are usually referred to as 
cements; but for building purposes cement means a much 
stronger kind of mortar than that which is usually referred 
to. Cement is obtained from silicious magnesian lime¬ 
stone. 

In order to obtain the cement the stones are burned in a 
kiln, in which process they lose one-third of their weight 
and acquire a brown color, varying in shade according to 
the color of the stone used. 

When the burning process is completed the fire is 
allowed to cool down, and when cool the stones, now in the 
form of blocks of cement, are removed from the kiln. These 
blocks of cement may be preserved for an indefinite time in 
the form in which they come from the kiln, if kept in a dry 
room. 

To prepare the burnt rocks for cement they are ground 
into a very fine powder, which is packed in tightly closed 
casks and in this form constitutes the cement of commerce. 

Cement must be kept from exposure to air, as it readily 
absorbs carbonic acid gas, and also from water, as it readily 
absorbs moisture, and both of these elements are very 
injurious to its adhesive properties. Its usefulness may be 
restored, however, by submitting it to a second burning at 
a much lower temperature than the first. 


112 


THE TEACHER'S AID. 


When designed for use the cement is mixed with suf¬ 
ficient water -to form a smooth paste, and in this form it is 
applied to the surfaces which it is designed to unite. 

The time required for the hardening or “ setting,” as it is 
usually called, varies considerably; when used in the pure 
state it will often harden in five or six minutes, and in order 
to give good results should not require over a half-hour. 

When used under water, as is sometimes the case, the 
time of hardening should not exceed one hour; when used 
in sea or salt water a longer time is required than in fresh 
water. The process of hardening is also retarded by the 
amount of sand used in the composition. 

Cements adhere strongly to iron, still stronger to granite 
and other rocky formations, but most of all to brick. 

Aside from the pure cements, many other forms or imi¬ 
tations are made by the mixture of burnt clays with rich 
limes, but they are of inferior quality, and their use can 
only be recommended on the score of economy. 

Other very important cements are those whose basis is 
composed of gypsum or plaster of paris, instead of the 
hydraulic limes. 

The uses to which cements are applied are various, the 
most important of which are for building purposes, the 
masonry of walls, bridges, abutments, piers, etc.; for pre¬ 
paring walks, floors, stairs and for ornamental decoration, 
and for mosaic work; for uniting pieces of spar, parts of 
marble ornaments, stoneware, pottery and pieces of broken 
glass, china, etc. 

Note: Remarks on cost, uses; manufacture, etc., of 
cement. 


THE TEACHER'S AID. 


113 


CHEESE. 

The cheese of commerce is the curd of milk separated 
from the whey and pressed into solid masses of various 
forms and sizes. It is usually made from milk alone, but 
that made from cream, or part cream and part milk, is 
richer, but does not keep so well. 

In the manufacture of cheese the substance known as 
rennet is generally made use of in the preparation of the 
milk. Rennets that are prepared from the stomachs of 
very young calves or pigs that have only been fed on milk 
are much better in quality than those made from stomachs 
of older animals that have had other foods. 

The rennets are prepared for use by taking the stomachs 
of these young animals and thoroughly cleaning them; they 
are then salted and dried and are allowed to stand for some 
time before using. 

When required for use, the rennet, or sometimes only a 
small portion of it, is placed in the sweet milk, and by its 
action the separation of the curd in a solid form is effected 
in from a half-hour to two hours’ time. 

When this stage is reached the curd is usually broken up 
in the vessel, and the temperature raised to about one hun¬ 
dred degrees. The mixture is next allowed to settle, and 
the whey is drawn off, after which the curd is wrapped in a 
linen cloth and placed in the cheese-press or mould. Before 
being placed in the press the temperature of the curd is 
reduced to about sixty degrees. 

The presses are strong tubs, usually made of thick elm 
staves held in place by iron bands or hoops. These tubs 
vary in diameter according to the size of the cheese desired; 
the depth is a little greater than that of the cheese intended 
to be made. 

The bottom of the tub is perforated with holes through 
6 


114 


THE TEACHER’S AID. 


which the whey escapes when pressure is applied. The 
tub containing the curd wrapped in linen cloth is placed 
in the press, and pressure applied, and at the end of an hour 
or a little longer it is taken out and the cloth removed and 
replaced by a clean one. 

In some factories, when the curd is taken out the first 
time, the salt, which is a necessary part of its compo¬ 
sition, is introduced; in other factories the salt is rubbed on 
the outside of the cheese as it is occasionally taken out of 
the press and put in again. 

It is submitted to the action of the press from twelve to 
twenty-four hours, or even longer, at the end of which time 
it is removed and transferred to the cheese room and placed 
upon a shelf. It is turned once a day for several days, and 
after that less frequently, until it is ready for the market. 

When cheeses are made very rich and large they some¬ 
times require to be bound together with strong linen bands 
in order to prevent their bursting while undergoing the 
process of drying. In some factories the cheese is treated 
to dippings in hot water, which process is supposed to 
harden the rind and also to hasten the process of internal 
fermentation. 

Coloring matter is sometimes added to the cheese during 
the process of manufacturing, but the best ones require no 
coloring matter. 

The size of cheeses varies in different places, being in the 
most places regulated by the amount of milk that can be 
obtained each day. In large factories, where a great 
amount of milk is obtained and the manufacture can be 
carried on, on an extensive scale, the cheeses weigh from one 
hundred to two hundred pounds each. But from twenty 
to sixty pounds are the most common sizes. 

Cheese is usually made from cow’s milk, but that 
made from the milk of goats and sheep, is said 


THE TEACHER'S AID. 


115 


to be excellent. That made from goat’s milk in 
central France, where great attention is paid to the 
raising of goats, is said to be highly esteemed. 

The Chinese have made a kind of cheese from very 
remote times from the pea and the bean; and in Saxony it 
is sometimes made from potatoes. When made from 
potatoes the following process is employed: To five 
pounds of boiled and mashed potatoes is added one pound 
of sour milk and a sufficient amount of salt to make the 
mixture taste right. The mixture is left stand for two 
or three days and is then kneaded and packed in little 
baskets and dried in the shade. 

This variety of cheese continues to improve in quality 
the longer it is left to stand. And when kept in well-closed 
vessels it will keep fresh for a number of years and is not 
so liable to engender worms as the varieties that are made 
of milk. 

Cheese is of a yellow color, varying from the lighter to 
the darker shades. Coloring matter is added by some 
manufacturers in order to give it a richer appearance. It 
is a hard, heavy substance and is more or less porous. 

Cheese is one of the chief products of the stock-raising 
sections of the country and is a very important manu¬ 
facturing industry. It varies in price according to the 
quality. Large quantities are manufactured and con¬ 
sumed annually. 

Note: Remarks on the cost, uses, manufacture, etc. 
of cheese. 

& & 

SAWDUST. 

Sawdust is the dust or small fragments of wood made by 
the action of a saw in wood, or the waste made by sawing 
timber. Formerly it was of little or no use, but now it has 


116 


THE TEACHER'S AID. 


become a material of some value in localities where it is 
produced, and where it can be utilized. 

It is used as a material for packing articles that are 
easily broken, for packing water-pipes to prevent their 
freezing, and as a packing for ice to prevent its thawing. 
But its most interesting application is in the manufacture 
of oxalic acid. In this respect it has been used with so 
much success as to almost displace all other methods of 
making that chemical. 

The process of converting the sawdust into this acid is 
very simple and is as follows: The sawdust is just satu¬ 
rated with a solution of soda and potash in the proportion 
of two parts of soda and one of potash; it is then placed in 
shallow iron pans which are connected with a furnace b}^ 
means of flues passing from the furnace under the pans. 

The iron pans are made hot, and the saturated sawdust 
runs into a semi-fluid, pasty state. It is stirred actively 
with rakes, so as to bring all parts of the sawdust into con¬ 
tact with the heated iron pan, and thereby granulate it for 
the succeeding operations. 

In this state it is oxalate of soda mixed with potash. It 
is then placed in a filter, and a solution of soda is allowed to 
run through it; this carries away all the potash and leaves a 
fairly pure oxalate of soda. 

It is then placed in a tank, in which it is mixed with a 
thin milk of lime; the lime combines with the acid to form 
oxalate of lime, and the soda is set free. After this the 
oxalate of lime is put into leaden cisterns, and sulphuric 
acid is poured in. This takes up the lime and sets free the 
oxalic acid, which readily crystallizes on the sides of the 
leaden cistern or on wooden pieces which are placed for this 
purpose. 

In color, sawdust is usually of a brown or brownish hue, 
but varies to either lighter or darker, according to the color 


THE TEACHER'S AID. 


117 


of the wood from which it is obtained. In weight it is very 
light and is capable of being greatly compressed. It is 
chiefly obtained in the lumber regions where saw-mills are 
in operation. It is a very inexpensive article. 

Note: Remarks on the cost, uses, etc., of sawdust. 

SILK. 

Silk is the product of the silkworm, or silkworm moth, 
of which there are many species. The most important is 
the common silkworm, which is a native of the northern 
provinces of China. 

When full-grown the moth is about an inch in length, 
the female being somewhat larger than the male; the wings 
are large and beautifully colored, usually whitish, with a 
broad, pale bar across the upper wings. Although in the 
different species the colorings and the arrangement of 
colors vary somewhat. The body is soft, encircled with 
alternate rings of white and brown and covered with a 
downy substance. 

The female moths generally die soon after they lay their 
eggs, and the males do not survive them very long. The 
eggs, which are numerous, are about the size of a pin head. 
They are not attached to each other, but are fastened to 
the surface on which they are laid by a gummy substance. 

The eggs are laid about the end of Summer and hatched 
about the beginning of the next Summer. 

When hatched, the caterpillar is very small, in fact not 
more than a quarter of an inch in length; but it rapidly 
increases in size, and when full-grown is nearly three inches 
in length. 

Some species are of a yellowish-gray color, while others 


118 


THE TEACHER'S AID. 


are black or brown. The head is very large in proportion 
to the size of the worm, and on the upper part of the last 
joint of the body there is a horn-like process. During the 
growth of the caterpillar the skin is shed four or five times. 

The natural food of the silkworm is the leaves of the 
white mulberry tree, but it will also feed on the leaves of 
some other plants, such as the black mulberry, the osage 
and the lettuce. But when fed on anything except the 
white mulberry, the silk produced is of an inferior quality. 

When full-grown and ready to spin its cocoon the silk¬ 
worm ceases to eat and commences the spinning process by 
producing the loose, rough fibres which form the outer part 
of the cocoon, and then the more closely wound and valu¬ 
able fibre or silk of the interior. 

The outer covering of the cocoon is a dry, coarse material 
very much resembling coarse paper in texture; it is a sort 
of a hull and is very much larger than the worm. It acts 
as a protection for the silk, which is spun in such a manner 
as to completely envelop the worm and fill the cocoon. 
This silk thread is spun in a continuous, unbroken thread. 

A single fibre of silk, or the contents of a single cocoon, 
will often exceed eleven thousand feet in length. 

The life of the silkworm in the caterpillar state does not 
usually extend over more than eight weeks. It requires 
about five days to complete the spinning of the cocoon, 
and after the lapse of two or three weeks the cocoon bursts 
open and the perfect insect emerges in the form of the silk¬ 
worm moth. 

The natural bursting of the cocoon, that is, when the 
insect cuts its way out, is very injurious to the silk, and in 
order to prevent this the insect must be killed w r hile in the 
cocoon. This is done by dipping the cocoons in hot water, 
or by placing them in heated ovens. This is done with all 


THE TEACHER'S AID. 


119 


the cocoons, except those intended for the production of 
eggs for the coming season. 

When the cocoons are completed, which is known by 
the absence of any sound from within, they are carefully 
sorted into the different sizes and grades. When the sort¬ 
ing is finished the cocoons are placed in an oven, where a 
gentle heat is applied, or by dipping them in hot water, 
which process kills the enclosed chrysalis; otherwise the 
silk contained in the cocoon would become perforated as 
the insect cuts its way through. And when once cut the 
silk would be worthless for spinning purposes. 

The cocoons .are made ready for winding by first remov¬ 
ing the outside covering, which is often tough and compact. 
In order to do this the cocoons are placed in vessels filled 
with water, and kept warm by means of charcoal fires; in 
some establishments these vessels are kept warm by the 
application of heat. 

The heat softens and dissolves the natural gum which 
coats the silk, and which also makes the various coils of 
silk adhere while in the cocoon. 

When this coating becomes dissolved the outer ends of 
the silk threads loosen and become detached; and in order 
to collect these ends the cocoons, while still in the water, 
are stirred with a small, branchy twig, which has several 
ends. 

As the cocoon softens in the water, the outer or first end 
of the web becomes loose, and in this way several loose ends 
soon become attached to the points of the twig. From 
three to five of these loose ends are taken and twisted with 
the fingers so as to unite in one thread; these threads are 
passed through a glass or polished metal eye of a reeling 
machine. 

The reeling machine is placed so far from the hot water 
vessel as to allow the softened gum on the silk time to dry 


120 


THE TEACHER'S AID. 


in passing from the vessel to the reeling machine. In large 
factories very complex machinery is sometimes used for 
winding. When one set of cocoons is unwound another set 
is taken, and so on until all the silk is transferred from the 
cocoons to the reeling machines. 

When wound the thread has next to be cleaned, after 
which it is doubled and twisted. The silk is now in the 
form of hanks, which have to be again wound on reels and 
bobbins, and when thus prepared they are ready for the 
weaver. 

The cleaning, winding, reeling and twisting are very 
slow processes and require great care and patience The 
thread in its natural color is a light yellow, but can easily 
be dyed any desired color or shade, and when so dyed pre¬ 
sents a very beautiful and pleasing appearance. 

Pure silk is a very expensive material; it is often inter¬ 
woven with other materials, such as woolen, cotton and 
linen threads. The fabrics produced by these mixtures are 
usually much cheaper than the all-silk cloths; but many of 
them are very pretty and serviceable. 

China is one of the chief silk-producing countries, but 
the cultivation of the silkworm has been introduced into 
many other countries and has proven quite a successful 
industry. The United States produces annually a large 
amount of silk of a very good quality. 

The chief uses to which silk is applied, are in the manu¬ 
facture of textile fabrics and thread. 

Note: Remarks on cost, uses, manufacture, etc., of 
silk. 


THE TEACHER'S AID 


121 


CANDLES. 

Candles are small cylindrical bodies made of tallow, 
wax, spermaceti and other fatty substances formed on a 
loosely twisted wick and used as a portable light. 

The tallow prepared from the fat of animals was used 
for the manufacture of candles, and at a still later period 
the fluid fat of the whale, or spermaceti, was used for the 
same purpose. The vegetable kingdom has also been 
largely drawn upon to furnish oils for the same purpose, as 
the palm and the cocoa nut. The mineral kingdom yields 
from bituminous coal a substance in the form of paraffine, 
another excellent material for the manufacture of candles. 

The common dipped candles have long been made by 
the introduction of cotton yarn wicks into melted tallow. 
The candles are brought to the required size by repeated 
dippings. In the early stages of the manufacture of can¬ 
dles this process was accomplished by hand work. 

Instead of the old-fashioned method of dipping by hand, 
a simply-contrived machine has been made for the per¬ 
formance of this work. It consists of an upright revolving 
post, which carries twelve horizontal arms, at the end of 
which is attached a frame of six rods; from each of these 
rods hangs eighteen wicks, making in all one thousand and 
ninety-six. 

As the post is turned round, each arm comes in succes¬ 
sion over a reservoir of tallow which has been prepared for 
the candles. The frames are so arranged that the wicks 
can be lowered and dipped into the melted tallow. 

And as the machine revolves, each set of wicks receives 
its application of tallow and is cooled as it revolves around 
before its turn comes for another dip. When the weather 
is not very warm, the whole frame full of wicks can be con- 


122 


THE TEACHER'S AID. 


verted into complete candles in the course of about two 
hours. 

An improvement upon the dipping process was made by 
the substitution of cylindrical moulds of the size of the 
candles desired. 

These moulds were made of tin or pewter, and a number 
of them were arranged in a frame; moulds of glass have 
recently been substituted for those of metal. The wick is 
secured through the center of each mould and the tallow 
poured in; the wicks are stretched tight and the moulds set 
away for the tallow to cool. 

The best candles used in this country are made of sperm¬ 
aceti. Wax candles are the most expensive kind, but are 
now little used compared with the other kinds. They are 
made by dipping and pouring the melted wax over the 
wicks. 

Shape is given to the wax candles during the dipping 
process, and at its close by rolling the candles between 
marble slabs; they are also sometimes shaped by drawing 
them through a machine made for the purpose, in much 
the same way in which wire is drawn. 

Much difficulty is met with in the moulding of wax 
candles, owing to the fact that the wax adheres to the 
interior surface of the mould. Wax candles require much 
smaller wicks than the other varieties; the wicks should be 
made of twisted, unbleached Turkey cloth. 

Immense quantities of candles are manufactured annu¬ 
ally and used for various purposes. Wax candles are used 
for church purposes chiefly, but sometimes for lighting halls, 
parlors, etc., where a great display is to be made; tallow 
candles are used for lighting dark places where it would be 
either too unhandy or dangerous to carry lamps; that is, in 
such places as mines, cellars, under buildings, etc., and as a 
bed-room light. 


THE TEACHER’S AID. 


123 


Wax candles, owing to the material used and the care 
required in making, are more expensive than the other 
varieties. Candles are usually of a white or creamy color, 
and of a smooth, waxy appearance. Some varieties are 
quite expensive, while others are very cheap. 

Note: Remarks on the cost, uses, manufacture, etc. 
of candles. 

COCOA NUT. 

The common cocoa nut of commerce is the fruit of the 
cocoa nut palm. These trees are natives of warm climates, 
and some species grow to a considerable height. 

The flowers are arranged in branching spikes from five 
to six feet long, and the fruit matures in bunches of from 
ten to twenty. The fruit, when fully matured, is of an 
oblong shape, with irregular cross sections, and measures 
from twelve to eighteen inches in circumference and six to 
eight inches in diameter. 

This fruit consists of a thick external husk or rind, within 
which is the ordinary cocoa nut of commerce. The nut 
has a very hard, woody shell, enclosing the kernel, within 
which is a milky liquid called cocoa nut milk. 

The uses to which the various parts of the cocoa nut 
palm are applied in the regions of their growth are almost 
endless. The nut supplies food, and the juice furnishes a 
refreshing drink. The juice which is drawn from the 
flowers forms a “ toddy ” which may be boiled down to a 
sugar, or when allowed to ferment forms a spirit known as 
“ arrack.” 

The trunk of the tree furnishes a timber which is used 
for building purposes, for furniture, for firewood, etc. The 
leaves are used for fans, baskets and for thatching purposes. 


124 


THE TEACHER'S AID. 


The shells of the nuts are used as water vessels, and the 
external shell yields a fibre from which ropes, cordage, 
brushes, etc., are made. 

Cocoa nut oil is obtained from the kernel either by press¬ 
ure or by boiling. The oil thus obtained is used in the 
manufacture of candles and soaps. Cocoa nut butter is 
obtained from the kernel also, and is used as a substitute 
for animal butter; it is a very pleasant, nutritious and 
fattening substance. 

The fibre obtained from the outer nut is used in the 
manufacture of coarse brushes, door mats, mattings for 
lobbies and passage ways, and for many other purposes. 
Cocoa nuts are shipped from their native countries to other 
and colder climates, where large quantities are consumed 
annually. Large quantities of cocoa nut oil and butter are 
manufactured and consumed, and are very important 
articles of commerce. 

Note: Remarks on uses, etc. 

& 

COCHINEAL. 

Cochineal is a dye-stuff obtained from an insect which 
is a native of the warm portions of America, Mexico in par¬ 
ticular. It is a small insect; the female is slow and stupid, 
the male being much smaller and more active. The body 
is wrinkled transversely, and the under side is of a deep red 
color, the anterior part bristly, and the legs short and black. 

The male is supplied with two sets of wings, while the 
female has none. 

This insect is found on several species of cactus, especi¬ 
ally on that known as Nopal, or Indian fig-tree. There are 
plantations of the Nopal, which are planted and cultivated 
for these insects, and upon which they feed. 


THE TEACHER’S AID. 


125 


These insects are tended with great care and in much 
the same manner in which the silkworm is cared for. Just 
before the rainy season in these warm countries, sets in, 
the branches of the Nopal that are covered with the insects 
are cut off and placed under sheds to protect them from 
the weather. 

When the proper time arrives the insects are collected 
and placed in a vessel, where they are kept for some time, 
and are then killed by the application of heat. The dead 
insects are thoroughly dried and ground into a coarse 
powder, which is known as the cochineal of commerce. 

On the plantations where these insects are raised the 
method of propagation is as follows: At the close of the 
wet season, or about the middle of October, the plantations 
are stocked by suspending little nests which are made of 
some soft, woody fibre and containing eight or ten of the 
females, upon the spines of the Nopal, or whatever kind of 
cactus the plantation is made of. 

Here the insects soon deposit their eggs, each one pro¬ 
ducing more than one thousand. These soon hatch and 
spread over the plantation, and when they have attained 
their growth they are gathered and made into cochineal. 

The males, which are few in number, are easily distin¬ 
guished from the females; they contain none of the color¬ 
ing matter, and are, therefore, not gathered, as they are 
valueless. 

The females are picked off the trees by means of a sharp, 
blunt knife, and the work is so tedious that a workman 
can only collect about enough to make two ounces of 
cochineal in a day. 

The first crop is collected about the middle of Decem¬ 
ber, and following crops are gathered as other generations 
of the insects are hatched and matured, the last crop being 
usually in May. 


126 


THE TEACHER'S AID. 


There are three methods employed in killing the insects, 
one being by placing them in a basket and dipping them 
in boiling water, by placing them on hot iron plates, and 
by placing them in hot ovens. 

When the drying process is completed the insects have 
the appearance of small grains which are concave on one 
side and convex on the other, and about one-eighth of an 
inch in diameter; the transverse wrinkles that appeared on 
the insect when alive are still visible. 

It is estimated that fully seventy thousand of these 
insects are required to weigh a pound. The coloring mat¬ 
ter is a brilliant red, which is very soluble in water and 
alcohol, but is not soluble in ether. 

This coloring matter is obtained by macerating the 
cochineal or pow r dered insect in ether and treating the 
residue with alcohol and evaporation. In this form it 
contains more or less fatty matter, which is removed by 
again dissolving it in alcohol and adding a small quantity 
of sulphuric acid, which causes precipitation in a few days. 

The better qualities of pigments known as lakes are 
made by mixing freshly-prepared alumina and cochineal. 
Owing to the time and trouble required to produce cochi¬ 
neal, and the uses to which it is applied, it is a very valu¬ 
able and expensive article, and for this reason it is fre¬ 
quently adulterated. The adulterations, although very 
inferior, take the place of cochineal to a great extent. 

Cochineal is used in the manufacture of pigments and 
dyes where red, or shades of red are required, and also to a 
certain extent for medicinal purposes. 

Note: Remarks on cost, uses, manufacture, etc., of 
cochineal. 


THE TEACHER'S AID. 


127 


LIMESTONE. 

Limestone is the popular, as well as technical name 
for all rocks which are composed in whole or to a large 
extent of lime. Few minerals are as extensively dis¬ 
tributed in nature as this, and in some form or other 
limestone rock occurs in every geological epoch. 

Carbonate of lime is nearly insoluble in pure water, but 
is rendered easily soluble by the presence of carbonic acid 
gas, which occurs in variable quantities in all natural waters. 
Carbonate of lime in solution is consequently found in the 
water of all lakes, rivers, seas and streams. 

Great changes may have taken place through meta- 
morphic action in the texture of the rock, as some lime¬ 
stones are hard, others soft, some compact, and others of 
a more porous nature. 

The chief varieties of limestone are: Chalk, compact 
limestone, a hard, smooth, fine-grained rock, generally of a 
bluish-gray color; crystalline limestone, a rock which, from 
metamorphic action, has become granular; saccharine or 
statuary marble is composed of fine-grained white varieties, 
resembling loaf-sugar in texture. Magnesian limestone is 
a rock in which carbonate of magnesia is mixed with car¬ 
bonate of lime. 

Limestone is used in the production of lime for mortar, 
plaster and lime for building and paving purposes. And 
in the form of lime it is used in the preparation of hides for 
leather. There are also many other purposes to which the 
products of limestone are applied, in the form of lime, etc. 

Note: Remarks on the cost, uses, preparation, etc., of 
limestone. 


128 


THE TEACHER'S AID. 


ALOE. 

Aloe is a genus of plants of which the species are numer¬ 
ous; they are natives of warm countries, particularly the 
southern part of Africa. These plants or trees vary in 
height from only a few inches to thirty feet. 

About fifty miles from Cape Town there is a vast moun¬ 
tainous tract which is completely covered with aloes, and 
they are also found in profusion on the hills west of Socrota. 

There is a variety found in the East Indies, the West 
Indies and in some of the islands of the Mediterranean sea; 
this is the only species that can be called European, and it 
is probably an imported plant. 

Ajnong the Mohammedans the aloe is a symbolic plant, 
especially in Egypt; and everyone, upon returning from a 
pilgrimage to Mecca, hangs a spray of aloe over his door 
as a sign that he had performed the journey. 

The aloes are generally valued for their medical prop¬ 
erties, for which qualities they have been known and used 
from very early times. 

The drug known as aloes is the inspissiated juice of the 
various species of aloe. 

The leaves of these trees are large, thick, fleshy, stiff and 
brittle, pointed and generally terminating in a strong spine; 
they are filled with a thick, mucilaginous pulp, and contain an 
intensely bitter juice which possesses the medical properties. 

Aloes is obtained by making incisions in the leaves, which 
causes the juice to appear in the form of tears or drops; by 
spontaneous exudation; by spontaneous evaporation of the 
juice which drops or exudes by pressure from the leaves 
when they are cut near the base. It is sometimes obtained 
by evaporating the same juice by means of heat and also 
by evaporation of the juice and a decoction of the leaves. 

But the usual way of obtaining the aloes is as follows: The 


THE TEACHER'S AID. 


129 


leaves are collected from the plants and placed in tubs, and 
when a large quantity has been procured they are boiled to a 
suitable consistency, or they are exposed to the action of the 
sun until all the fluid part has been expelled by evaporation. 

All varieties of this drug are remarkable for their dis¬ 
agreeable taste, which is extremely bitter and acridy. It 
also has a very peculiar odor, which becomes more per¬ 
ceptible when the drug is heated. 

Aloes is soluble in water, hot water causing it to dissolve 
more readily than cold water. It was formerly considered 
as a gum, but is now usually classed as an extract. 

When used in small doses it acts as a tonic, and in large 
doses as a cathartic. It is also considered as a stimulant 
for the liver by supplying the deficiency in bile. 

The juice of aloes was used by the ancients as an embalm¬ 
ing fluid to preserve dead bodies from putrefaction. In 
the east it is used as a varnish to prevent the attacks of 
insects; it has also been applied to the bottoms of ships in 
order to protect them from marine worms. The aloes also 
furnishes a beautiful violet coloring from its leaves, and a 
fine transparent color for miniature painting. 

There are many varieties of aloes sold in the form of 
drugs for medical purposes, as the Socrotine aloes, obtained 
from Socrota, an island in the Indian ocean; the hepatic or 
common Barbadoes aloes, and the fetid or caballine aloes, 
the last named being a very coarse kind, consisting of many 
impurities, such as wood, sand, charcoal, etc.; it is usually 
composed of the dregs left in the vessels where the better 
grades have been made, and is considered only fit for horses. 

In Africa the leaves of some species are made into dur¬ 
able ropes; others are made into fishing-lines, bow-strings, 
stockings and hammocks. The leaves of another species 
are made into cups that will hold water. 

Remarks on cost, uses, manufacture, etc., of aloes. 


130 


THE TEACHER’S AID. 


ALBUMEN. 

Albumen is an organic substance which forms one of the 
principal ingredients of both the animal fluid and the vege¬ 
table formation. It is found in an almost pure state in the 
white of an egg. 

It exists in the sap, seeds and the edible parts of many 
plants. It is a transparent fluid, soluble in water, and in 
such a state of solution is found in the white of the egg, in 
the juice of the flesh, the serum of the blood, and the juices 
of vegetables; when heated, it coagulates and ceases to be 
soluble in water. 

The coagulation of albumen by the application of heat 
makes it a very valuable substance for clarifying purposes, 
in sugar refineries and in the manufacture of syrup, molas¬ 
ses, etc. 

When used for this purpose the albumen is usually 
mixed with the liquid while in a cold state, and upon being 
heated it coagulates and collects all the impurities and 
separates them from the liquid. 

The albumen is much lighter than the syrups or liquors 
and rises to the top, carrying with it all impurities; these 
are readily removed by skimming. 

Albumen forms the principal part of many vegetable 
substances. It is the most important part in the grain of 
corn, coffee, cocoa nut and many other seeds, nuts and 
grains; and for this reason it forms a very important part 
in most foods. 

Note: Remarks on uses, etc., of albumen. 


THE TEACHER’S AID. 


131 


QUICKLIME. 

Quicklime is a pure oxide of calcium and is obtained by 
driving off by heat carbonic properties from the marble, 
limestone or other carbonates of lime. 

It is a white, caustic powder and combines readily with 
water to form slaked lime. Quicklime is employed in many 
useful ways; it is a valuable ingredient in mortar and is 
largely used as a fertilizer. 

Note: Remarks on uses, cost, etc., of quicklime. 

CHARCOAL. 

Charcoal is the more or less pure form of carbon obtained 
from various vegetable and animal materials by their igni¬ 
tion. There are two kinds of charcoal, vegetable and 
animal charcoal. The former is obtained from the vege¬ 
table and the latter from the animal kingdom. These two 
productions vary very much in form and appearance, and 
are also very different in the uses to which they are applied. 

Wood-charcoal is a very black, brittle, porous sub¬ 
stance ; it is devoid of both taste and smell, and retains the 
form and external structure of the wood from which it is 
obtained. It is infusible and is not dissolved by the action 
of either water or acids; and when ignited it burns without 
flame. 

Charcoal, when freshly burned, rapidly absorbs atmos¬ 
pheric moisture. The quality of charcoal obtained from 
wood varies according to the nature of the wood employed 
and the method of manufacturing it. 

Charcoal can be prepared in different ways. In its pure 
form it is obtained from organic substances such as sugar 


132 


THE TEACHER’S AID. 


and starch. That form of charcoal made for use in powder 
mills, and also that produced in acetic acid factories, is 
produced by the distillation of wood in iron cylinders. 

In China charcoal is prepared in pits, preferably in a 
clay soil. In some parts of Sweden it is made of rectangu¬ 
lar piles of wood, the operation being carefully regulated 
by the admission of air through holes in the covering of the 
wood. 

In most countries where wood is abundant charcoal¬ 
burning is carried on to a great extent. The wood is felled 
in the Winter and allowed to become fairly dry before 
using; it is then built up in conical piles with the largest 
pieces in the center, and the side with the bark on is placed 
outermost and uppermost. When the pile is completed it 
is covered over with charcoal-dust, turf or soil. 

The burning of the pile is conducted from the top down¬ 
ward and from the exterior toward the center. Along the 
sides of the heap, holes are made in the covering for the 
admission of air. 

The first or “ sweating ” process, as it is called, covers a 
period of three or four days; during this time the covering 
becomes damp from the effects of the condensed moisture 
within. 

The openings around the sides at the base of the pile are 
now closed, and another series of holes is made about half 
way from the top of the heap. From these holes the smoke 
issues after ignition first takes place. When the smoke 
ceases to issue from these holes, which is the case after the 
wood has become consumed from the top downward to or 
past the holes, they are then closed, and others are made 
as required. 

When the air-holes of the burning heap cease to emit 
smoke they are all closed carefully, and the heap is allowed 
to stand for two or three days until it becomes cool. By 


THE TEACHER'S AID. 


133 


following the above method, one hundred and twenty-eight 
cubic feet of wood will yield about thirty bushels of char¬ 
coal. 

Wood charcoal is used as a fuel, for medical purposes 
and in the manufacture of filters. Its principal use is in 
the manufacture of gunpowder; it is also a valuable absorb¬ 
ent of noxious effluvia and a good disinfectant. It is used 
for kindling fires in furnaces, etc. 

Large quantities of wood charcoal are manufactured 
and consumed annually. It is a product of the timber 
districts and is usually a very inexpensive article. 

Animal charcoal, or bone-black, is prepared by igniting 
flesh and bone which have been previously boiled to remove 
the fat, in closed vessels of iron or earthenware. 

Lamp-black is the chief form of animal charcoal; it is 
obtained by condensing the smoke of burning, resinous and 
oily substances. The crude lamp-black is purified by 
heating to redness in closed vessels. 

Animal charcoal is used as a pigment in the form of 
ivory-black. It is also used as a fertilizer for soils which 
are intended for vegetable productions. As an antidote in 
cases of phosphorus poisoning it has been highly recom¬ 
mended. 

Animal charcoal is a black, oily, sticky substance, hav¬ 
ing a disagreeable smell. There is a decided difference in 
the form and appearance of the two kinds of charcoal, as 
well as in the ways in which they are utilized. Both are 
very important and useful substances. 

Note: Remarks on cost, uses, manufacture, etc., of 
charcoal. 


134 


THE TEACHER'S AID. 


DYE-STUFFS. 

Dye-stuffs are substances used to give color, other than 
the natural color, to articles such as cloth, leather, wood, 
glass, paper, horn, earthenware, etc. They are obtained 
from the animal, mineral and vegetable kingdoms. The 
greater number being derived from the vegetable king¬ 
dom. 

The dye-stuffs obtained from this kingdom are numer¬ 
ous and are found in every part of the world. Plants of 
widely different families yield this coloring matter, and it 
is obtained from the root, bark, leaves and stem. 

There are different ways of preparing these substances 
for use as dyes. In some instances the bark, leaves, etc., 
are dried and left in this form; in other cases they are 
ground into a powder. 

Some of the chief vegetable dyes are logwood, peach- 
wood, sumac, walnut and indigo. The mineral dyes are 
obtained from coal-tar, copperas, tin, lead, zinc, iron, etc. 
While from the animal kingdom we obtain cochineal and 
indirectly the nut-gall. 

The numerous materials used as dye-stuffs produce 
many beautiful colors and shades. And when two or more 
of the coloring materials are used in combination, many 
colors and shades are produced besides the original ones. 

The materials to be dyed are usually bleached before 
dyeing, except for the darker shades. Iieat and water, or 
heat and steam, are used in applying the dye; and in setting 
the color, in order that it may remain fixed or permanent, 
alum, cream of tartar and salts of tin are used. 

Some of these dye-stuffs are very expensive, while others 
are produced at a trifling cost. 

Remarks on colors and combinations of colors, cost, 
uses, durability of colors, etc., of the different dye-stuffs. 


THE TEACHER’S AID. 


135 


RESIN. 

Resin is a vegetable product composed of carbon, hyd¬ 
rogen and oxygen. It resembles the essential oils, which, 
when exposed to the air, absorb oxygen and are eventually 
changed into substances possessing the properties of resin. 

At ordinary temperature resin is solid, hard and brittle, 
and either slightly colored or transparent. Some resins 
have a very strong, aromatic odor, owing to the presence of 
essential oils, while others are destitute of odor. 

Resin melts readily when heated, and is very inflam¬ 
mable. It is insoluble in water, but readily dissolves in 
ether, alcohol or any of the oils. 

There are three varieties of resin; they are the hard, soft 
and gum. The hard resin, which, at an ordinary tempera¬ 
ture, is solid, brittle and easily pulverized, and which con¬ 
tains very little or no essential oil. The soft resins, which 
can be molded by the hand, or some of which are semi-fluid, 
and when in this form are known as balsams. The soft 
resin consists in reality of hard resin in solution with essen¬ 
tial oils; and when exposed to the air it oxidizes and 
becomes hard resin. Gum resin is the milky juice of some 
plants, which, when exposed to the air, becomes hard; it 
consists of a combination of resin, essential oil and gum. 

Resin is very lavishly distributed throughout vegetable 
life, some plants possessing it to a greater degree than 
others. The usual method of obtaining this substance is 
by making an incision in the wood of the tree producing it. 

In some cases the resin exudes from natural causes, 
such as cracks, knots and through the bark, in which case 
the tree does not need to be cut. In other cases the resin 
is extracted by boiling the wood in alcohol. 

The crude resins are separated from the essential oils, 
with which they are usually mixed, by distillation with 


136 


THE TEACHER’S AID. 


water. In this process the oil and water pass off, and the 
resin remains. The gummy and sticky matter is then 
removed by alcohol, which dissolves the pure resin, and it 
is then separated from this by the addition of water. 

Several species of pine yield the common resin or the 
resin of commerce. It is obtained by cutting off a longi¬ 
tudinal slice of bark and wood; this is done with an ax 
having a curved blade, and leaves the incision grooved or 
with an inward curved surface. 

At the bottom of this groove is placed a spout made of 
a small piece of bent wood, tin or zinc, which serves to 
catch the fluid resin as it flows from the cut in the tree. 
From these spouts the fluid passes into small pots of baked 
clay, which have been placed to receive it, and which are 
emptied when filled, and The contents taken to the distil¬ 
lery, where the essential oil is removed. 

All impurities are then removed, and it is molded into 
shape, and then in the form of hard resin is ready for the 
market. 

Resins are extensively used in medicine, in the prepa¬ 
ration of varnishes, pigments, soaps, artificial lights, in 
manufactures and in the arts. 

Remarks on cost, uses, etc., of resin. 

jt, 

CAMPHOR. 

Camphor is an essental oil which is found in many 
plants. It is principally a product of the laurel tree, the 
most important of which is the camphor laurel, a native of 
China, Japan, Cochin-China and the West Indies. 

This tree attains to quite a height and has many branches. 
It is an evergreen, the flowers of which are yellowish-white- 


THE TEACHER'S AID . 


137 


and the fruit in size and appearance is very much like the 
black currents before they become ripe. 

Every part of the plant smells strongly of camphor, but 
the flowers possess this quality in a greater degree than the 
other parts. The wood which is very light and durable, is 
very valuable. Owing to the strong odor, the laurel is 
seldom injured by insects. 

To procure the camphor, the wood of the branches and 
stems is chopped into fine particles and placed in a vessel 
with water. This vessel is in the form of a still, and when 
heat is applied the camphor rises with the steam produced 
and is carried off in the form of vapor. 

The head of the still, into which the vapor passes, is filled 
with rice straw, and when the vapor reaches this the cam¬ 
phor solidifies and is converted into minute grains about 
the size of grains of sand, or sugar which are deposited on 
the straw. 

These camphor grains are collected from the straw, put 
into large glass vessels and melted. When first heated the 
water is allowed to escape through a small opening in the 
top of the vessel. This opening is soon closed, and the 
camphor then rises in a vapor and solidifies into a semi¬ 
transparent cake in the interior of the upper portion of the 
vessel. 

The camphor of commerce is a tough, solid, whitish 
substance, with a bitterish taste and a very strong, fragrant 
smell and a peculiar hot, aromatic taste. It is lighter than 
water and only partially soluble in it, but readily dissolves 
in the essential oils, ether, acetic acid and alcohol. It is 
inflammable and melts readily. 

Camphor is used medicinally, both internally and exter¬ 
nally. If taken in small doses it is beneficial, but in large 
doses is a strong poison. 

It is extensively used in the preparation of liniments 


138 


THE TEACHER’S AID. 


and in applications for rheumatism, sprains, bruises, etc. 
It is also largely used for preserving insects for natural 
history specimens. 

Remarks on uses, cost, etc., of camphor. 

^ ^ ^5 

TEAK. 

Teak is the name applied to two kinds of wood, which 
are valuable for ship-building and other purposes. 

One variety is known as Indian teak, and the other as 
African teak. The trees which produce these two woods 
are of very different orders. 

Indian teak is found in the mountains of Malabar, and 
in other parts of Hindostan, and in the Eastern Peninsular, 
Java and Ceylon. It is a beautiful tree, attaining a height 
sometimes of as much as two hundred feet and rising above 
all other trees of the East Indian forest. 

It has deciduous leaves, which grow from twelve to 
twenty-four inches long and are covered with points. The 
flowers, which are white with five or six clefted corolla, 
grow in great panicles. The fruit is a four-celled drupe 
about the size of a hazle nut. 

Its flowers are used for medicinal purposes, while the 
leaves are used by the Malays in cases of cholera. A purple 
dye is obtained from the leaves; this dye is used in the col¬ 
oring of silk and cotton materials. 

Teak wood is the most valuable wood produced in the 
East Indies. It is light, strong, durable, and not subject 
to the attack of insects. 

On account of its extreme lightness it is easily handled 
and carved or cut into any desirable shape. In texture it 
closely resembles coarse mahogany and contains an abund¬ 
ance of silex. 


THE TEACHER'S AID. 


139 


Owing to its lightness and durability, it is extensively 
used in ship-building. All the finest ships that are built in 
India and England are made of teak. 

The African teak is a wood very similar to the East 
Indian teak, but as it is not in as general use as the East 
Indian teak, it is not so well known. 

Remarks on cost, uses, etc., of teak. 

& ^8 & 

GRANITE. 

Granite is a rock of a granular texture, composed of 
quartz, mica and feldspar. 

These minerals are united in an irregular way, the feld¬ 
spar being usually most abundant, the quartz next and 
mica last in proportion. These proportions vary, however, 
and the variety of granite depends on the amount of these 
ingredients and their distribution throughout the rock. 

There are many varieties of granite, and they are found 
widely distributed over the earth’s surface. They are 
usually found in mountain regions, although sometimes 
found in the surface rocks of rolling plains. 

The texture is more or less granular, and the grains vary 
in size from that of a pin’s head to a mass of two or three 
feet; the usual size is that of a nut. The color is greatly 
diversified by the different parts of which it is composed. 
It is generally either white, grayish-white or flesh-red, and 
sometimes a combination of all these colors. 

Granite admits of a very high polish, and owing to its 
hardness and chemical composition it is not injured by 
exposure to the heat or cold, or by the action of the wind 
and weather. 

Granite is a valuable building material for houses, public 
buildings, bridges, etc. It is also largely employed in the 
making of tombstones and monuments. 


140 


THE TEACHER'S AID. 


Owing to its extreme hardness, it cannot be cut with 
saws, like ordinary building stones. But is made into the 
required shape by the use of large hammers or sledges, and 
then with sharp, pointed chisels and mallets. 

Great care must be taken and much time spent, and for 
this purpose skilled workmen are required; these workmen, 
if sufficiently skilled, are paid a high rate of wages. 

The difficulty experienced in working with granite, and 
the high rate of wages paid to the workmen, make it an 
expensive building material. Its durability, however, 
pays for the time and expense. 

Remarks on cost, uses, etc., of granite. 

S & 

BORAX. 

Borax is a native salt found in the form of an incrusta¬ 
tion on the shores and bottoms of some of the lakes in 
North America, China, Persia, Ceylon, Thibet and the East 
Indies. 

In its native state it is called tincal and contains impur¬ 
ities which are removed by the action of caustic soda, 
which removes the fatty matter with which the crystals in 
their native state are coated. 

Borax is also formed by boracic acid and carbonate of 
soda in boiling water. It is soluble in water, has a clear 
color and a sweetish taste. It can easily be pulverized, 
when it becomes a white powder and is known as powdered 
borax. 

It is extensively used in chemistry. It is used in the 
manufacture of glass and enamel and in the glazing used 
for pottery, and also in the paste used for making artificial 
gums. 

It is used in the fusion of metals, and is a great aid in 


THE TEACHER’S AID. 


141 


separating the different metals; also in the soldering of 
metals, by forming a coating which prevents the metals 
from oxiding while being united. 

Borax forms an important article in the dyeing of cloth 
and is extensively used in many domestic operations. 

Remarks on cost, uses, etc., of borax. 

& & 

COAL. 

Coal is a solid, opaqe mineral found at various depths in 
the earth. It is considered to be of vegetable origin and is 
found in strata or beds. It is of a black or blackish-brown 
color and of a more or less lustrous appearance. Some 
qualities admit of being polished to a high degree. 

It is of a hard, flinty or slaty structure and can readily 
be broken into particles. It is usually obtained in lumps, 
varying in size from very small ones to large ones weighing 
hundreds of pounds, and in some instances in large, smooth 
slabs. 

Coal is divided into two kinds, anthracite, which, when 
kindled, does not produce a flame, and the bituminous, 
which does. These are commonly known as hard and soft 
coal and are divided into a great, many varieties, as cannel, 
nut, block, lump, etc. 

The theory now generally believed in, as to the formation 
and origin of coal, is that the vegetable growths of former 
ages in low lands, sunk below the water and were gradually 
covered with sand, mud, etc., and sunk below the level. 
This process was continued till several layers were formed 
and the ground raised above the level. 

This buried mass was then acted upon by chemical 
forces in the earth and became converted into the substance 


142 


THE TEACHER’S AID. 


now known as coal. Various theories are, however, held as 
to its real origin and formation. 

Coal fields, or beds, are found in almost all parts of 
Europe, North America and in some countries of South 
America. The coal fields of North America, particularly 
those of the United States, are noted for their area and for 
the quantity and quality of coal which they produce. 

The production and sale of coal is a very important 
industry, as coal forms the chief article of fuel, both for 
heating and manufacturing purposes. 

The method of obtaining coal when it occurs near the 
surface is to dig a tunnel into the hillsides where such veins 
are usually found. These tunnels are extended in the 
direction in which the vein of coal extends, and are widened 
out into places called “rooms,” which are made by the 
removal of the coal by digging. 

As the coal is loosened and removed, strong wooden 
props are placed to retain the earth and a small portion of 
the coal overhead. These props prevent the earth from 
caving in and filling the rooms and entries. 

When a room is dug out as far as considered safe it is 
abandoned and the entry extended farther and new rooms 
made. These rooms and entries are so low in many places 
they will not permit a person to stand erect. They are 
damp and so dark that the workmen have always to carry 
lights. 

The coal, when dug, is put on small cars or trucks that 
are run on tracks in the entries. These loaded trucks are 
drawn from the entries by mules. 

This is the simplest method of coal mining and can only 
be employed in places where the coal occurs near the sur¬ 
face. When coal is obtained from many hundreds of feet 
below the surface the process is much more complicated 


THE TEACHER'S AID . 


143 


and dangerous. And in order to bring the coal to the sur¬ 
face a shaft is sunk to the depth of the vein of coal. 

This shaft is fitted with machinery suitable for lowering 
and hoisting whatever may be necessary for use in digging 
the coal and raising it to the surface. From the bottom of 
the shaft, entries, tunnels, rooms, etc., are made, which 
extend in all directions in which the coal extends. From 
the various rooms the coal is removed on small cars and 
collected at the bottom of the shaft, and from there it is 
hoisted to the surface. 

Daylight never penetrates into these mines. The work¬ 
men, machinery, tools, horses and mules and whatever is 
necessary for the operation of the shaft finds its entrance 
and exit through the shaft. 

Many deaths occur yearly through accidents, impure 
air, carelessness and other causes. The work is hard, the 
hours long and the pay usually low. 

In many places the wages are too small to cover the 
living expenses of the laborer, and on this account the 
miners often strike for higher wages and shorter hours for 
work. These strikes often cause a great amount of want 
and suffering, and serious riots often occur in mining dis¬ 
tricts during a strike. 

Coal is almost indispensable for heating and manufac¬ 
turing purposes, and great quantities are used annually 
for these purposes. The prices of coal vary as to the kind 
and the quality; also according to the demand and supply 
and the season of the year. 

Note: Remarks on the uses, cost, production, etc., of 
coal. 



144 


THE TEACHER'S AID. 


WHISKY. 

Whisky is a spirit made by distillation from grains, roots 
and other materials. The best quality is produced from 
barley after it has been malted, though that produced from 
wheat, oats, rye, rice, buckwheat, Indian corn, millet, etc., 
when kept for several years, is almost as good. 

It is also made from potatoes, beans, beet root, carrots, 
sugar, molasses, etc. Whisky and all other intoxicating 
spirits are obtained by fermentation and distillation. 

Alcohol is the essential element of all spirits and is pro¬ 
duced by the decomposition of sugar, which is changed into 
carbonic acid and alcohol by the process of fermentation. 

Sugar being the direct source of alcohol, all vegetable 
products containing it may be used in the manufacture of 
alcohol or spirits. 

Starch is a vegetable substance that can easily be con¬ 
verted into sugar and thus becomes indirectly a source of 
alcohol. All substances that contain either sugar or starch 
or both will yield spirits. The first step with starch is to 
convert it into sugar. When the substance used is sugar 
the process consists of fermentation and distillation. 

The grain or vegetable substance to be used is ground 
or mashed and mixed in a vat with water at a high tem¬ 
perature. This mixture is agitated for two or three hours, 
and the saccharine infusion drawn off and cooled. 

To this is now added a quantity of yeast or barm, which 
induces fermentation and resolves the saccharine matter 
into alcohol and carbonic acid. The alcohol mixture thus 
obtained is called “ wash ” and is now ready for distillation. 

This takes place in an apparatus called a “ still.” This 
still consists of a copper vessel provided with a close head, 
terminating in a bent tube, which passes in a spiral form 
(the worm) through a vessel filled with cold water. 


THE TEACHER’S AID. 


145 


When heat is applied to the still the spirits begin to rise 
in a vapor, along with more or less steam. These vapors 
pass through the worm, become condensed by the cold, 
and drop or trickle in the form of liquid into a receiver. 

This liquid is then re-distilled at a lower temperature to 
remove the water and injurious oils that had passed over 
with the alcohol. 

To obtain great strength and purity, repeated distilla¬ 
tion is used. If only water and alcohol pass over in distil¬ 
lation, all spirits, from whatever extracted, would be the 
same. But this is not the case, as the various vegetable 
substances have each their own peculiar essential oils, 
which in distillation they impart to the spirits which they 
produce, thus giving to each their various distinguishing 
flavors. 

The principal intoxicating beverages produced by dis¬ 
tillation are brandy, rum, gin, ale, whisky, arrack, etc. 
Whisky, alcohol and the various other spirits are largely 
used for medicinal purposes. 

Note: Remarks on uses, cost, production, etc., of 
whisky. 

jt jt 

ALUM. 

The alum of commerce is a compound of salt; it is an 
astringent substance of a whitish color. It is soluble in its 
own weight of hot water, and in about eighteen or twenty 
times its weight of cold water, and in astringent acids. 

It liquifies when heated, and when the water is expelled 
by heat crystallization takes place, and a spongy, white 
mass remains, which is known as burnt alum. 

Alum is obtained in Sweden, England, Italy, Scotland 

and in many of the countries of South America. It rarely 

10 


146 


THE TEACHER'S AID. 


occurs in a pure state, except in a few springs and in some 
extinct volcanoes, where it seems to be formed by the 
action of sulphuric acid vapors upon feldspar rocks. 

It usually occurs in clay and rock. It is also prepared 
artificially from alum-rock. In the manufacture of alum 
different processes are employed according to the nature of 
the substance from which the alum is to be extracted. 

The ordinary means used being heat or water, or a com¬ 
bination of both. The processes vary in different alum- 
works. In the ordinary method the alum-stone is broken 
into small particles and piled on the top of a perforated 
dome, in which a fire of wood has been kindled. The 
smoke and flames of the wood penetrate through the pieces 
of alum-stone, and a sulphurous odor is emitted, owing to 
the decomposition of a portion of the sulphuric acid con¬ 
tained in the stone. This roasting is repeated once or 
twice. 

The process of roasting the stone requires much careful 
attention, for if the heat is too great the quantity of alum 
produced is diminished; and if the heat is too small the 
stone is not easily reduced to a powder. 

It is generally acceded that the unroasted stone would 
yield more alum than the roasted stone, but it requires 
much more time and labor to reduce the unburned stone to 
a powder, and the loss of alum in the burned stone is fully 
made up by the saving of time and labor required to work 
with the unburned stone. 

The roasted stone, which has assumed a reddish color, is 
placed in rows between trenches that are filled with water. 
The stones are kept wet by frequent sprinklings of water 
from these trenches, and in a few days they fall to powder 
like slaked quicklime; but the daily use of the water is 
continued for at least a month. 

The progress of this part of the operation is said to 


THE TEACHER’S AID. 


147 


depend to a certain extent on the weather. When the 
weather is rainy the alum is all washed out and very little 
left for the manufacturer. 

When the stone has been reduced to a sufficiently fine 
powder it is put in a leaden boiler which is partially filled 
with water. It is next subjected to a boiling process, dur¬ 
ing which time it is frequently stirred, and as the water 
evaporates it is replaced. 

When the boiling is completed the fire is withdrawn, 
and the earthy matter in the fluid is allowed to settle to 
the bottom of the vessel. The clear liquid is then drawn 
off into deep, square wooden vessels; these vessels are so 
constructed as to be easily taken apart. The alum gradu¬ 
ally crystallizes and adheres to the sides of these vessels. 

The mother liquid, or the liquid that does not crystal¬ 
lize, and which is now of a red color, is drawn off; it has a 
muddy appearance and is used again in subsequent pro¬ 
cesses. The crystals are washed clean and are now in the 
form of the alum of commerce. 

In this form they are hard, clear and almost transparent 
and have a peculiar, bitterish, acrid taste and are devoid of 
smell. 

In the manufacture of alum in Sweden, where fuel is 
scarce, a small pile of brush-wood is made and the alum stone 
is piled on it and a fire is started. When the slate has become 
heated other slate is piled on, and the already heated slate 
is made to serve the purpose of fuel; in this way a large 
quantity of slate is burned with the use of very little fuel. 

The burning process is kept up for as much as six weeks. 
The burnt slate is then put into a large receiver and covered 
with water; after about twelve hours the water is drawn 
off into wooden vessels, where the alum granulates and 
becomes the alum of commerce. 

Alum is used in coloring and dyeing processes, where a 


148 


THE TEACHER'S AID. 


fast color is required; it is used in the preparation of leather; 
in the making of bread by bakers in order to give the bread 
a white and more pleasing appearance; it is used in medi¬ 
cine as a wash for sores and ulcerations, as an astrin¬ 
gent to stop bleeding, in the manufacture of some 
paints, and for many other purposes. It is quite an inex¬ 
pensive article. 

Note: Remarks on cost, uses, manufacture, etc., of 
alum. 

jt jt, 

TOBACCO. 

The plant from which tobacco is obtained belongs to the 
natural order solanacece. It has large, broad leaves, a 
five-parted calyx, funnel-shaped five-lobed corolla and five 
stamens; the flowers grow in panicles at the top of the stem; 
the fruit, a ttvo-celled five-valved, many-seeded capsule. 

The species are mostly herbaceous plants, rarely shrubby 
with large, broad leaves and everywhere covered with 
clammy hairs. They are natives of warm countries, most 
of them American, although some of them are found in the 
East Indies. 

They all possess the narcotic property, on account of 
which a few of them are extensively cultivated. This nar¬ 
cotic property is found in all parts of the plant, although 
the leaves are almost exclusively used. 

The smoking of tobacco was found by Columbus to be 
practiced in the West Indies, where the natives made it 
into cylindrical rolls, wrapped in the maize leaf. It has 
been prevalent among the American Indians from unknown 
antiquity, as far north as Canada. 

With them it even has a religious character and is con¬ 
nected with their worships and in all their important trans- 


THE TEACHER'S AID. 


149 


actions. Thus the calumet, or pipe of peace, is indispens¬ 
able to the ratification of a treaty of peace, and smoking 
together has even a greater significance of friendship than 
eating together has among other nations. 

The cultivation of tobacco requires a rich soil, and the 
strongest fertilizers are very advantageously used. The 
influence of soil, climate and fertilizers used is very great, 
almost beyond what is known in any other cultivated plant. 

The cultivation of the tobacco plant is very easy, and 
although a warm climate suits it best, it is raised without 
much difficulty in most parts of Europe. 

The usual plan in the great tobacco-producing countries 
is to sow the seed in seed-beds of rich soil, and as the seed 
is extremely minute, it is first mixed with a large quantity 
of sand or wood ashes to assist in spreading it thinly on the 
ground. 

In Virginia, which may be taken as one of the best 
tobacco-growing districts, the seed sowing is usually done 
in the first week in January. 

After the seed-beds have been carefully prepared and 
sown, small branches of trees are laid over the beds to pro¬ 
tect the seeds when they germinate, from the effects of the 
frost, but are removed as soon as safety will permit, and the 
plants then grow rapidly and are ready for transplanting in 
the field about the middle of June. 

The land in the field is very carefully prepared, and 
small hillocks are raised up in rows; each is about a foot in 
diameter and flattened at the top. With the first appear¬ 
ance of rain the plants are carefully raised from the seed¬ 
beds and carried usually by children, who deposit one at 
each hillock, on which they are carefully planted by expe¬ 
rienced men, who follow after the children. 

Only wet earth will do for planting, so that this opera¬ 
tion lasts till the end of July. When planted, the tobacco 


150 


THE TEACHER'S AID. 


crop requires much careful attention and weeding, and 
constant watching to prevent the ravages of various insect 
enemies. Much of this latter work is done by flocks of 
turkeys kept for this purpose by the planter. 

As soon as the plants begin to throw up the flower- 
shoots they are nipped off; otherwise it would weaken the 
leaves; but this process is neglected in some countries, 
where small leaves are preferred, and where, as in some 
cases, leaves, buds and flowers are used. 

The time generally chosen for cutting is in mid-day, or 
when the sun is powerful, and the morning and evening 
dews absent. The cutting is done by hand, and only such 
plants are chosen as are ready, which is known by a clammy 
exudation which forms over the leaf, often giving it a spot¬ 
ted appearance. 

If the plants are very large the stalk is often split down 
in order to facilitate the drying. They are then removed 
from the field to the tobacco-house, around which are 
erected light scaffolds, to which the plants are suspended, 
generally by passing a thin stick through a split in the stalk 
of each, and thus placing a number of plants on each stick, 
just near enough to prevent them touching each other. 

After hanging in the open air for some time, the plants 
on the sticks are removed and suspended in a similar way 
inside the curing-house until the drying is complete. 

The leaves are next removed from the stalks, and all bad 
ones are rejected. The chosen ones are tied up in bundles 
called “hands,” and these are packed in hogsheads, enorm¬ 
ous pressure being applied in the packing. 

Cigars and cheroots are forms of manufactured tobacco. 
Snuff is also a form of manufactured tobacco. It is formed 
by grinding the leaf either with or without the leaf-stalk 
and midribs. The grinding is generally effected in wooden 
mortars, with pestles of wood. Some kinds of snuff are 


THE TEACHER’S AID. 


151 


prepared from kiln-dried tobacco, while others are made 
from the soft leaves. 

The varieties of snuff are numerous, and manufacturers 
who have been fortunate enough to make a snuff that has 
become a favorite have made fortunes. 

Tobacco is used as a sedative or narcotic over a larger 
area and by a greater number of people than any similar 
substance, opium being the next to it in this respect, and 
the hemp plant the third. 

There are a great many different kinds and grades of the 
manufactured tobacco, and the prices vary according to 
the quantity raised and the demand for the article. 

Note: Remarks on the uses, abuses, cost, cultivation, 
etc., of tobacco. 

jt & 

OYSTER. 

The oyster is a bivalve found adhering to rocks or other 
fixed substances, in shallow salt water and in the mouths of 
rivers. The shell consists of two uneven, irregular-shaped 
pieces, held together by a ligament fitted in a small cavity 
in each. 

The oyster is one of the lowest and simplest of the animal 
kingdom. Its food consists of animalcules, and also 
minute particles of vegetable matter, carried to it by the 
water, a continual current of which is brought to the mouth 
by the action of the gills. 

The species of the oyster are numerous and are found in 
the seas of all warm and temperate climates. None has 
been found in the coldest parts of the world. 

Oysters grow very rapidly and are ready for table use in 
a year and a half to two years. The young oysters readily 
attach themselves to the shells of old ones, and thus, in 
favorable circumstances, oyster banks or beds increase 


152 


THE TEACHER'S AID. 


rapidly. The usual mode of catching oysters is by dredg¬ 
ing, but it is very destructive to the oyster beds. But 
owing to the fact that they are covered by considerable 
water at all states of the tide, no better method has yet 
been devised. 

Fishermen, in their anxiety to make the most of their 
opportunity, cause many oyster beds to be destroyed by 
over-dredging. The formation of artificial oyster beds has 
been resorted to and yielded very satisfactory results. 

Numerous methods are employed in the preparation of 
artificial oyster beds, by supplying suitable solid objects for 
them to adhere to. 

Stones are piled together in such a manner as to leave 
open spaces among them. Stakes are driven into the sand 
or mud, and bundles of sticks are fastened to stones or 
stakes. Floors of boards are formed at a short distance 
from the bottom, and various other devices are employed 
to give the oysters a secure place to attach themselves and 
thus form the foundation of an artificial oyster bed. 

Oysters in some localities are much better than those 
produced in other localities. Oysters raised in artificial 
beds are called “natives” and are considered superior to 
those that are dredged from natural beds. Raw oysters 
are considered more nutritious than the cooked ones. 

The United States has an immense oyster trade. 

Note: Canned oysters, oyster shells, uses, etc. 

K* |T 

VANILLA. 

The vanilla of commerce is obtained from the vanilla 
plant, which is a native of the tropical pprtions of Asia and 
America. 

Although springing at first from the ground, it is a para- 


THE TEACHER'S AID. 


153 


sitical plant. It attaches itself to trees and fastens its 
fibrous roots into the bark, from which they extract the 
sap, on which the plant is sustained even after the main 
root has been destroyed. 

These roots are produced from nodes or joints, which 
also produce the leaves, which are long and fleshy. The 
vine climbs with a twining stem and attains the height of 
from twenty to thirty feet. 

The stem of this vine is four-cornered. The flowers 
grow in spikes, are large, fleshy and fragrant. The fruit, 
which is pod-shaped, is about eight inches long and less 
than an inch in thickness and is a fleshy capsule, opening 
along the side. 

To obtain vanilla, the fruit is gathered before quite ripe 
and is dried in the shade and steeped in a fixed oil. 

Within the pod is a soft, black pulp, which constitutes 
the most aromatic part of the fruit, and within this pulp 
many minute black seeds are found. 

Vanilla is classed among the essences, or essential oils, 
and has a strong, peculiar, agreeable odor and a warmish 
taste. It is a thin transparent, fluid and is used in pastry, 
confectionery, perfumery and liquors, and to a limited 
extent in medicines. It is one of the leading products of 
Mexico, Central America and some of the South American 
countries. 

Remarks on the uses, cost, etc., of vanilla. Plantations, 
cultivation, etc. 

jZ jt 

CUTTLE-BONE. 

Cuttle-bone is the bone of the cuttle fish. It is blade¬ 
shaped in form and in texture is very much like some 
varieties of light, porous rock. It is composed of carbon¬ 
ate of lime and is very light and porous. 



154 


THE TEACHER'S AID. 


In color it is a light grayish or grayish-yellow. It is 
easily reduced to a powder. 

It is used in the manufacture of tooth-powders, for pol¬ 
ishing purposes, for forming moulds for small silver castings 
and for various uses in the arts. It was formerly used as a 
medicine, but any other form of carbonate of lime is as 
good. 

Cuttle-bone is frequently placed in birds’ cages; and the 
birds, by picking the bone, derive the benefit of the car¬ 
bonate of lime. 

Remarks on the cost, uses, etc., of cuttle-bone. 

j* ^ 

QUILLS. 

Quills are the large feathers of the wings of birds, the 
hollow tubes of which, being properly cleaned of all oily 
and fatty matter and dried, are used for making pens to 
write with. Those plucked from geese are most generally 
used, but swan and turkey feathers are made use of. 

While for very fine writing and for pen-and-ink draw¬ 
ings crow quills are preferred to all others. The collection 
and preparation of quills at one time was a very important 
industry, but the manufacture of and introduction of metal¬ 
lic pens reduced it to very narrow limits. 

When the quills have been collected they are carefully 
scraped, cleaned and dried by a very moderate heat in 
ovens. The application of heat in this manner gives them 
the required brittleness in the lengthwise direction of the 
quill, which is a very necessary property for them to pos¬ 
sess. For without the required brittleness they could not 
receive the fine split which constitutes their chief merit, as 
it is upon this that the entire writing character of the pen 
depends. 

Quill pens have been almost entirely superseded by the 


THE TEACHER'S AID . 


155 


metal pens, while in olden times, before the manufacture of 
metal pens, the quill pens were universally in use. 

Metal pen-points are generally very inexpensive, 
although some, as the gold ones, are higher-priced. They 
are a very necessary and indispensable article. 

Remarks on cost, use and history of the quill and metal 
pen. 

jt 

ROPE. 

Rope is generally made from vegetable fibres, but is also 
made from wire. The fibre generally used is hemp, but 
large quantities of plantain fibre, or Manila hemp, cotton, 
and rattan are also used. 

Rope consists of many thicknesses or threads and was 
formerly made by hand, but is now machine made. The 
two processes are similar, the machine work having the 
advantage of rapidity. Rope is made by taking threads 
of the fibre to be used and twisting them into strands. 

Then the required number of strands is taken; these are 
twisted separately and are then twisted together. In this 
manner the strands fit closely into each other, and the 
result is, a round rope is produced. 

They are either hard or soft according to the material 
used and the amount of twisting they have received. Dif¬ 
ferent numbers of strands are used, and the ropes vary in 
size according to the use for which they are designed. 

The strength of machine-made rope can be calculated 
with surprising exactness. Tarred ropes are noted for their 
strength and durability and are made by the thread or yarn 
being drawn through a preparation of hot tar. The surplus 
tar is removed by drawing the tarred thread through a hole 
lined with oakum. 

Great care and ingenuity have been devoted to the manu- 


156 


THE TEACHER'S AID. 


facture of rope, owing to the great amount of life and prop¬ 
erty depending on the strength and durability, in its use 
for ships, shipping and for building purposes. 

Iron rope has been introduced and is largely used in 
ship-rigging, for building purposes and wherever great 
strength is required. It is generally made from iron wire 
and is usually galvanized. 

The greatest bridges are suspended over rivers and held 
in position by iron rope. They are adjusted to the ex¬ 
tremes of heat and cold and are so arranged that they will 
not snap or break suddenly. 

Remarks on rope, how and where used. 

£ t 

JET. 

Jet is a bituminous mineral of a compact texture and a 
perfectly black color and susceptible of a good polish. It 
has a glossy, velvety appearance where broken or fractured. 
It is not harder than ordinary coal, but is easily cut or 
carved into any desired shape and polished to a high degree. 
Jet is in reality only a peculiar form of pitch-coal. 

When rubbed, or when any kind of friction is applied, 
it becomes quite electrical, and hence it has been called 
“black amber” by the Prussian amber diggers when it 
occurs in sand or gravel beds. Large quantities of jet are 
found in France, Spain, Prussia and England. 

It furnishes employment to numerous artisans, who 
form it into beads, crosses, buttons, toys, ornaments and 
other articles of jewelry. 

As a material for mourning ornaments and jewelry, jet 
is admirably adapted, and for this purpose is used largely 
in this and other countries. Very beautiful and expensive 
jewelry ornaments are made from jet. 

Remarks on cost, uses, etc., of jet. 


THE TEACHER’S AID. 


157 


RATTAN. 

Rattan is a genus of palm very different in habit from 
most of the order. It has a long, slender, reed-like stem, 
which is smooth, hard and often jointed. 

There are many species, and all very useful. The 
rattan-palms are found in the East Indies, Southeast Asia, 
Southern India and the islands adjacent to these countries. 

They are used by the natives for making wicker-work, 
rope, bridges, etc. Bridges are made of these palms in 
some of these eastern countries and are very strong and 
durable. 

Ropes made from them are used for many purposes 
requiring great strength, among which is the tying of the 
untamed elephant. Cables for the use of ships and vessels 
in these regions are made of rattan. 

Small stems of rattan are prepared and used as a sub¬ 
stitute for whalebone. The fruit of some species and the 
young stems or shoots are used for food. 

Rattan is imported to other countries under the name of 
cane. These canes are put up in bundles of one hundred 
canes. They vary in length from fifteen to twenty feet, 
and when used are cut into the desired length. 

Note: Remarks on the uses, etc., of rattan. 

^ & 

QUININE. 

Quinia, or quinine, is a compound derived from the 
bark of different varieties of chinchona. It is most abund¬ 
ant in the pale Peruvian bark, which forms one of the chief 
products and exports of Peru. 

The quinine of commerce is in the form of a powder, 
composed of small, white, glistening particles; it has an 


158 


THE TEACHER'S AID. 


intensely bitter taste and is soluble in alcohol or ether, but 
not in water. 

To obtain the quinine, the bark, which has been removed 
from the trees and dried, is pulverized and boiled with 
water containing one per cent of oil of vitriol, which dis¬ 
solves and separates the ingredients present. 

Quinine is used for medical purposes, not only as a cure 
for diseases, but as a preventative. It is a tonic and is 
very effective in cases of chills and fever. 

It is used very successfully in many forms of disease, 
alone and with other medicines. It is noted for its bitter¬ 
ness of taste and for its white, glistening appearance. 

Note: Remarks on cost, uses, etc., of quinine. 

& 

i 

SODA. 

Soda, or, more correctly speaking, carbonate of soda, 
occupies the chief place among the leading chemical manu¬ 
factures, from its influence on other great chemical 
industries, such as glass-making, bleaching, etc. 

A native carbonate of soda is found in Egypt, and some 
other parts of the world. In Hungary several manufac¬ 
tories exist for the purification of a native soda found there. 

Formerly, most of the soda in use was extracted from 
certain plants. But the quantity of soda from all other 
sources is insignificant in comparison to that manufactured 
from common salt. 

Soda has also been called a fixed alkali, in order to 
distinguish it from ammonia, which is a volatile alkali. 
The carbonate of soda which was formerly called “natro” 
was obtained by lixivating the ashes of marine plants, or 
decomposing the salts of soda. In this state it is, however, 
seldom pure. 


THE TEACHER'S AID. 


159 


In the manufacture of soda, the first operation is the 
production of sulphate of soda. And in doing this, the 
decomposition of common salt is effected by treating it 
with sulphuric acid, which changes it into sulphate of soda, 
and hydrochloric acid. 

This process is accomplished by means of a furnace. 
When the furnace is properly heated, the desired amount 
of salt is thrown in, and a quantity of strong sulphuric 
acid is heated and added to the salt; this mixture is 
stirred with an iron rake. It gradually thickens into 
a pasty mass, in about an hour, and is removed from the 
furnace through an opening into the salt-cake chamber. 

In this chamber it is spread out and kept at a red heat 
for another hour, at the end of which time all the hydro¬ 
chloric acid is expelled, and the mass is converted into 
sulphate of soda. 

The second operation consists in changing the sulphate 
of soda into Black-asti, or, as it is sometimes called, “ Ball 
Soda.” This is done by heating a mixture of sulphate of 
soda, carbonate of lime and coal in a reverberatory furnace. 
During this process the sulphate of soda is converted into 
sulphide of sodium; then the sulphide of sodium and the 
carbonate of lime are converted into carbonate of soda 
and sulphide of calcium; and finally the excess of lime is 
reduced, by the carbonate, to caustic lime and carbonic 
oxide. 

The third operation is the preparation of soda from the 
Black-ash. This is done by lixivation and evaporation. 
In some of the operations the crude soda or Black-ash is 
used without further purification; as in the making of soap. 

The lixivation is carried on by means of a series of iron 
tanks or vats into which the Black-ash and water are 
placed. A series of these tanks are placed one above an¬ 
other, so that the liquid which is placed in the highest can 


160 


THE TEACHER'S AID. 


be emptied into the next lowest, and so on, until it has 
passed through the seires of tanks. 

The Black-ash is introduced first into the lowest vat; 
it is passed from vat to vat upward, and when exhausted 
is taken away at the highest one. And in opposition to 
this, the water is first introduced at the top and passes 
downward; in each successive vat, as it passes downward, 
it encounters stronger and less exhausted ash, and when 
it passes away from the lower vat it is a fully saturated 
solution. 

The next process is the evaporation of soda-lye; this 
operation is conducted in a variety of ways, a very com¬ 
mon method being to use the waste heat of the boiling- 
furnace, the flame of which is made to pass over the surface 
of the liquor. The heat imparted in this way causes rapid 
evaporation. In the process of evaporation, the soda falls 
to the bottom and is removed at intervals through a side 
door, and drained upon a sloping surface. 

The soda-salts, which are thrown off by evaporation, 
contain caustic soda and sulphide of sodium, which it is 
necessary to remove. They are accordingly placed in a 
reverberatory furnace and calcined at a moderate heat. 
Sawdust, and sometimes small pie'ces of coal, are mixed 
with the soda-salts, the mixture being stirred with iron 
paddles. 

By this operation the caustic soda is converted into 
carbonate of soda, and the sulphur is mostly expelled, and 
the product remaining is the soda-ash or alkali of com¬ 
merce, which generally contains about fifty per cent, of 
real soda; the other ingredients being chiefly water, sulphur 
and common salt. Sometimes it is further purified and is 
then known as white alkali. 

Various processes have been at times proposed, and 
many have been patented, for making carbonate of soda 


THE TEACHER'S AID. 


161 


by other methods. One of these patents consists in treat¬ 
ing a solution of common salt with bi-carbonate of am¬ 
monia, by which bi-carbonate of soda is produced. 

Remarks on uses, etc., of soda. 

* 5 * & 

LEATHER. 

Leather consists essentially of the skins of animals chem¬ 
ically altered by the vegetable principle called tannin, or 
tanic acid, so as to arrest that proneness to decompose, 
which is so characteristic of all soft animal substances. 

The invention of leather reaches beyond the dawn of 
history, and was probably among the germs of earliest civi¬ 
lization. For, as the skins of animals would naturally be 
among the first articles of clothing, any means of preserving 
them more effectually than by drying would be highly 
prized. The discovery that bark had this effect was 
doubtless an accident. 

The skins of all animals used in the production of 
leather consists chiefly of gelatine, a substance which 
easily enters into chemical combination with the tannic 
acid found in the bark of most trees, and forms what may 
be termed an insoluble tanno-gelatin. 

The theory of tanning, or converting hides into leather, 
consists in subjecting the hides or skins to the action of the 
tannin. Formerly oak-bark was supposed to be the only 
tanning material of value; but lately many numerous addi¬ 
tions have been made to this economic branch of botany. 

In addition to the process of tanning in the making of 
leather, there are other modes, one of which is “tawing ” 
and another “ dressing in oil 

The following are the skins which form the staple of 
our leather manufacture: Ox, cow, calf, buffalo, horse, 

sheep, lamb, goat, kid, deer, dog, seal, hog, etc. 

11 


162 


THE TEACHER'S AID. 


The first process is to soak the hides or skins in water 
for a greater or less time, in order to wash and soften them; 
they are then laid in heaps for a short time, and afterward 
hung in a heated room, by which means a slight putrefac¬ 
tive decomposition is started, and the hairs become so 
loose as to be easily detached. 

This process of unhairing is mostly followed in America; 
but in Great Britain, milk of lime is used for soaking the 
hides till the hairs become loose. 

If the old method of tanning is followed, the hides, after 
having the hairs removed, are placed in the tan-pit, with 
layers of oak-bark or other tanning material between them. 
When the pit is filled, water is let in, and the hides remain 
to be acted upon by the tanning material for months, and 
even for years in some instances, being only occasionally 
turned. 

But this is a primitive process that is now rarely carried 
out. So much improvement has been made in the tanner’s 
art since its chemical principles were discovered that much 
less time suffices; and materials are now used which act so 
much more quickly than oak-bark alone that even if the 
old process is used it is greatly accellerated. 

A process has been patented within the last few years 
by which the heaviest hides can be converted into leather 
in a very short space of time. 

Tanning consists in dressing the skins with antiseptic 
materials so as to preserve them from decay. When the 
hides are thoroughly tanned and dressed they are then in 
the form known as leather. 

Leather is often carved and stamped in very pretty 
designs, as seen in belts, saddle equipments, harness, etc. 
It can also be colored any desired color or shade. 

The uses to which leather is applied are various, some of 
the most important being the manufacture of boots and 


THE TEACHER'S AID. 


163 


shoes, harness accessories, belts, drum heads, in the uphol¬ 
stering of furniture and various other articles too numerous 
to mention, but all more or less useful and ornamental. 

The application of water to some kinds of leather, as 
buckskin, causes it to shrink greatly. The price of leather 
varies according to the kind and quality and also according 
to the amount consumed and the supply to fill this demand. 

Note: Remarks on cost, uses, preparation, etc., of 
leather. 

^ 

PLATINUM. 

Platinum is one of the “ noble metals ” and is obtained 
in various forms. It is only found in the native state, 
usually occurring in glistening particles of a steel-gray 
color, which always contain, in varying proportions, an 
admixture of several metals, most of which are seldom 
found except in association with platinum. 

Sometimes, however, it is found in masses of the size of 
a pigeon’s egg, and pieces weighing ten or even twenty 
pounds have been found. 

There are two modes of obtaining platinum in the form 
of ingots from the ore. After the metals that are asso¬ 
ciated with the platinum have been removed the platinum 
is dissolved in aqua riga, from which it precipitates by the 
use of sal ammonia in the form of a sparingly soluble double 
salt. 

This salt is washed and heated to redness, by which 
means the chlorine and ammonia are expelled, leaving the 
metal in the form of a gray, spongy, soft mass known to 
chemists as spongy platinum . In this form it is very finely 
powdered under water and is next shaped by intense press- 
use into a mass and is then exposed to an intense heat in a 
wind-furnace, the ingot being formed by hammering it on 


164 


THE TEACHER'S AID. 


its ends. This heating and hammering must be repeated 
till the metal becomes homogeneous and ductile. 

An entirely different method is the following: First, 
form a fusible alloy of this metal with lead by exposing the 
platinum ore with equal parts of galena and litharge gradu¬ 
ally added, and a' little glass to act as a flux, to full redness 
in a reverberatory furnace lined with clay. 

The sulphur of the galena is oxidized and expelled, and 
the liquid alloy of lead and platinum is allowed to rest for 
some time. The upper portions of the alloy are then 
decanted and cast into ingot-moulds, which are submitted 
to cupellation, and the metallic platinum which is left, is 
melted and refined in a furnace of lime. 

The platinum obtained in this manner is pure, or nearly 
so, and very ductile and malleable. Platinum may be 
easily alloyed with other metals, the alloys being in general 
more fusblie than the pure platinum. 

Platinum is used for a variety of purposes, among which 
are the making of wire, as platinum is very easily drawn 
out and into what is known as “foil,” etc. 

Note: Remarks on cost, uses, etc., of platinum. 

JZ 

POTTERY. 

Pottery is the name applied to all objects or vessels made 
of baked clay. It is earthenware glazed or unglazed and 
baked. The knowledge and use of pottery dates from 
remote periods. 

Pottery was first made and used in the unglazed state 
in which form it was very rough and porous. It soon 
became dirty and discolored from use or exposure. The 
invention of glazing was soon introduced and proved quite 
an improvement over the unglazed ware. The glazed 


THE TEACHER’S AID. 


165 


pottery does not discolor or become dirty from use or age, 
as the unglazed pottery does. 

The manufacture and improvement has so increased that 
in place of the crude vessels and ornaments made and used 
by the ancients we have now the most delicate, beautiful, 
costly and at the same time most useful works of art. Many 
of the vases of ancient times were quite pretty and are now 
treasured as very valuable works of art. 

The readiness with which clay could be worked into any 
desired shape when mixed with water, and the hardness 
which it could be made to acquire either by exposure to the 
sun or by the application of heat, were qualities which 
commended its early use in the manufacture of pottery. 

There are a great many varieties of clay which differ 
very much in quality, durability and purity. Clay usually 
contains many impurities, which, unless they can be re¬ 
moved, make it unfit for use in pottery. Great care must 
be taken in the selection of the clay used in the manufac¬ 
ture of this ware. Kaolin is the purest kind of potter’s 
clay. 

The different kinds of pottery-ware are china, queens- 
ware, delf, porcelain, etc. The method of obtaining or 
making the different kinds being the same, or about the 
same, the only difference being in the kind and quality of 
the clay used. 

In the manufacture of this ware the chief materials used 
are clay, flint, rock, lime, bone glass, etc. These are 
ground fine by separate mills and are reduced to soft, pasty 
masses by the action of water while being ground. 

These materials are then thoroughly mixed with water. 
When well incorporated, they are allowed to subside, and 
the water is then drawn off; the mixture that is left is of 
the consistency of tough dough, and is very plastic. This 



166 


THE TEACHER’S AID. 


plastic substance, or prepared clay, is now ready for 
moulding. 

It is then moulded into objects of the desired shape, 
by means of the hands and machinery. When moulded, 
it is dried, fired, decorated and glazed, and is then ready 
for the market. The clays used are sometimes tinted and 
colored before being moulded, while again the coloring is 
done after the objects are moulded. 

Some of the articles made from pottery are evry beau¬ 
tiful in design and workmanship, and are very expensive; 
others are quite plain and inexpensive. The objects made 
of this ware are numerous, and comprise the following: 
Dishes, vases, urns, ornamental objects, and many others 
too numerous to mention. 

Note: Remarks on cost, uses, manufacture, etc., of 
pottery. 

jit & & 

SALT. 

Salt is the chloride of sodium, and is used for seasoning 
certain kinds of food, and for the preservation of meats, etc. 
It is found native in the earth, or it is obtained by evapo¬ 
ration and crystallization, from water impregnated with 
saline particles. 

Common salt is either found in the crystal state, called 
Rock-salt, or as a native brine from wells or springs, or by 
the evaporation of sea-water. 

The crystal, or rock-salt, is obtained by mining, often 
at a very great depth. This salt always contains many 
impurities; and in order to free it of these impurities it is 
dissolved in water, when the insoluble impurities sink to 
the bottom; the brine is then drawn off and evaporated 
by artificial heat, in large iron pans. 

Native brine is obtained by digging shafts; from these 


THE TEACHER’S AID . 


167 


shafts the brine rises to the top and overflows, if not 
pumped off. Reservoirs are made for it, into which it 
flows or is pumped, and from which it is distributed to the 
various works, where it is evaporated. 

These works are composed of sheds, which have numer¬ 
ous openings in their roofs, through which the steam 
escapes. Flues pass from one end of these sheds to the 
other, on the floor. The iron pans or evaporators, which 
are about sixty-five feet long by twenty-five broad, and 
about eighteen inches deep, are placed upon these flues. 

The flues heat the brine nearly to a boiling point, and 
as a large surface is exposed, the evaporation is very rapid, 
and the crystals are small; such as we find in the fine 
table-salt. If, however, the heat is more gentle, the salt 
is coarser; such as is used for curing meat, fish, etc. And 
when the evaporation is very slow, a much coarser kind, 
called bay-salt, is obtained. 

Salt is obtained from sea-water in many parts of the 
world. This is effected by simply evaporating it in brine- 
pits, or shallow square pools, dug for this purpose on the 
shore where the brine is obtained. 

When the evaporation has proceeded to a certain extent, 
the liquid assumes a reddish color; a crust of salt forms on 
the surface, which soon breaks, and sinks, and is followed 
by another; and the crystallization then proceeds very 
rapidly. 

When evaporation and crystallization are complete, the 
salt is removed to sheds which are open at the sides, and 
piled in heaps, in order that the chloride of magnesium 
may be removed. 

This is very easily done, as it liquifies by exposure to 
the atmosphere and runs out from the salt. The salt is 
then re-dissolved and crystallized, if great fineness is re¬ 
quired. 


168 


THE TEACHER’S AID. 


When the salt has been obtained, it is packed in barrels 
or sacks and is now ready for the market. It is a very im¬ 
portant article of commerce, and although an article of 
staple and daily use, it is quite inexpensive. The price 
varies according to the kind and quality. Rock-salt is 
largely used for live-stock. 

There are extensive salt mines in Germany, Poland, 
India, the United States, and many other parts of the 
world. Some of the salt wells in operation are many hun¬ 
dred feet in depth. 

Note; Remarks on cost, uses, mining, preparation, etc., 
of salt. 

HOUR-GLASS. 

The hour-glass is an instrument for measuring time. It 
is made of glass, and in form consists of two bulbs united 
by a narrow neck, or tube. 

One of the bulbs is filled with dry sand, and the instru¬ 
ment is placed on a stand or table, with the part containing 
the sand uppermost. The sand passes through the small 
opening between the bulbs, the time being measured by 
the passage of the sand from the upper to the lower bulb. 

The quantity of the sand is proportioned so as to pass 
from one glass to the other in an hour; or a half hour, a 
quarter hour, or minute. The amount of sand usually 
requires an hour for passage, hence the name “ hour-glass.” 

When the sand has all run through to the lower part, 
the instrument is inverted, and the sand proceeds to run 
back to the lower, and empty, part. 

This instrument was found very defective, as the orifice 
was expanded or contracted by the action of the heat and 
cold, and the sand was hastened or retarded in its passage. 


THE TEACHER'S AID. 


169 


The moisture or the dryness also produced variations from 
the true measure of time. 

The hour-glass was almost universally used in churches 
during the sixteenth century, and continued in use in 
many places even to the present century, but is entirely 
out of use at the present time. 

Hour-glass stands of beautiful design and workmanship 
are still to be found in many of the old churches in England. 

Note: Remarks on cost, uses, maunfacture, etc., of the 
hour-glass. 

SOAP. 

Soap is a compound made of one or more of the oil-acids 
with the metallic acids, potassa or soda, and also with 
some other substances which unite readily with these oils. 

The most common soaps are made by boiling some 
common oil with the lye of wood ashes. Common soap is 
a fat, oily, greasy substance. 

The chemical composition of soap is as follows: The 
fixed, fatty bodies, stearine, palmatine and oiline, when 
heated with alkaline solutions, and when they undergo the 
change known as saponification or conversion into soap. 
In this operation the fats yield a clean, viscid liquid, which, 
owing to its sweetness, is called glycerine. 

The term soap is often extended so as to include com¬ 
pounds made of the fatty acids mixed with other bases 
besides the alkalies. But these preparations or compounds 
are insoluble and therefore not appropriate for the purpose 
of scouring and cleaning. The true soaps owe their clean¬ 
ing properties to their solubility. 

In the manufacture of soap in this country, as well as in 
other countries, the ingredients used are tallow, lard, palm- 
oil, bone-grease and kitchen fat, boiled in solution with 


170 


THE TEACHER’S AID. 


caustic soda. Cocoa, palm-nut and some other oils are 
occasionally used, chiefly in the imitation of the superior 
grades of soaps. The only other ingredient of any con¬ 
sequence which is used in the manufacture of soap is resin. 

In the manufacture of soap the maker first dissolves a 
quantity of crude soda-ash in boiling water. This is done 
in a circular iron vessel or boiler, which is furnished with 
steam-pipes in the middle. Half the weight of pure caustic 
lime is then added and the mixture boiled. 

When the lime has made the soda caustic the boiling is 
discontinued and the mixture allowed to settle, when the 
lye is ready for use. The pans used in the manufacture of 
soap are of various sizes; one of very moderate dimensions 
will turn out from six to eight tons. 

These pans are usually formed of four pieces of cast-iron, 
the lower casting being about five feet in diameter and the 
upper one about eleven feet. 

Heat is applied either by means of a furnace at the 
bottom or by steam introduced by a pipe leading to a per¬ 
forated circular ring at the bottom of the soap-pan. 

The fats to be used and a quantity of prepared lye are 
put into the pan. Heat is applied and continued until the 
boiling point is reached; it is still further continued at a 
gentle rate till the lye is thoroughly incorporated with the 
tallow or fat used, and they are formed into a fatty mass. 

In this form it is known as soft soap. For hard soap a 
quantity of common salt is now added, and the lye begins 
to separate. The partially formed soap is now allowed to 
cool, and the salted lye, which has settled to the bottom, is 
drawn off by a pipe or else removed by means of pumps. 

The operation of adding salt to the boiling lye and fat is 
repeated till the fat is saturated with soda, and the lye 
exhibits as much alkali after as before boiling. Weak lye 
or water is now added till the mixture is of the desired con- 


THE TEACHER'S AID. 


171 


sistency. The heat is removed and the soap readily be¬ 
comes solid. 

It is then cut in slabs by the use of wires, and these slabs 
are again cut transversely into squares or bars. Some 
soaps are colored and perfumed and moulded into pretty 
cakes and bars; these are usually stamped and lettered 
either with the name of the manufacturer or the name of 
the soap, and sometimes with both. 

These bars and cakes are usually wrapped in paper and 
packed either in wooden or paper boxes, and in this form 
are ready for the market. 

Some of the finer soaps are very expensive, while others 
are quite inexpensive. Soaps are used for cleaning and 
scouring purposes, and medicinally. The only kind of soap 
that should be used internally is white soda soap, which is 
prepared from caustic soda and either olive or almond oil. 
When in its purest state it is known as medical soap. 

All soaps are soluble, and to this fact may be attributed 
their cleansing properties. The manufacture of soap is car¬ 
ried on quite extensively and is a very important industry. 

Note: Remarks on cost, uses, manufacture, etc., of 
soaps. 

SULPHUR. 

Sulphur is a yellow, brittle substance; it is insoluble in 
water, and fuses by the application of heat. It is also 
known as brimstone, from the name burn-stone, which 
means combustible. When ignited it burns with a bluish 
flame, and emits a peculiar, suffocating odor. 

Sulphur is found widely distributed in the mineral king¬ 
dom; it is sometimes free, and again combined with other 
elements. Natural sulphur is of two kinds; the common and 
the volcanic. 


172 


THE TEACHER’S AID. 


The free sulphur is either found pure, in regularly 
formed crystals, or closely mixed with earthy matters. In 
the form of sulphide, it is found closely mixed with copper, 
zinc, lead, iron, etc. Sulphuric acid is chiefly manufac¬ 
tured from sulphide of iron. 

The sulphates of sulphur, which are found in magnesia, 
baryta, etc., occur more abundantly in nature than the 
sulphides do. In the vegetable kingdom, sulphur occurs 
as a constituent part of the albuminous portions of the 
plants, and also of such volatile, irritant oils as mustard, 
garlic, asafoetida, etc. It is also an important constituent 
in the animal kingdom. 

In the manufacture of sulphur from the mineral sub¬ 
stances in which it is found, the impurities are removed 
by fusion and distillation, at, or near, the place where it is 
obtained. 

Refined sulphur is that which is purified by being dis¬ 
tilled in a large cast-iron still, and condensed in a receiver. 
The principal compounds of sulphur are, refined sulphur, 
sublimed sulphur, flowers of sulphur, stick sulphur, black 
sulphur, sulphur of ivy, and milk of sulphur. 

Sulphur is employed extensively in the arts, and for 
manufacturing purposes, but its chief use is in the manu¬ 
facture of sulphuric acid. It is also used in the manufac¬ 
ture of matches, gunpowder, and as a bleaching compound 
for textile fabrics, straw, etc., and in the extermination of 
insect life, fungi, and the like. 

Sulphur is used in many different ways for medicinal 
purposes; in the form of an ointment, for external appli¬ 
cation; internally as a laxative; it is used as an antiseptic, 
and as a disinfectant; and as a preservative for meats. 

Sulphur is one of the most important of the non-metallic 
substances. At ordinary temperature it is a solid body of 


THE TEACHER'S AID. 


173 


a yellow color, tasteless and inodorous. It is insoluble in 
water, but fuses when subjected to heat. 

The sulphur producing countries are Sicily, Italy, Mora¬ 
via, Poland, Iceland and Mexico. 

The sulphur of commerce is in the form of a fine yellow 
powder, and is quite inexpensive. 

Note: Remarks on the cost, uses, manufacture of sul¬ 
phur. 

TIN. 

Tin is a metal of a white color, with a tinge of yellow; it 
is soft, non-elastic, and very malleable. It is softer than 
gold, and can be beaten into very thin sheets, in which 
form it is known as tin-foil. 

It is a fairly good conductor of both heat and electricity, 
and when handled imparts a peculiar odor to the skin. 
There are many valuable and useful ways in which tin is 
employed, but the chief one seems to be in the manufacture 
of utensils for cooking purposes. When used in this way, 
it is usually alloyed with copper, antimony and bismuth 
in small proportions. 

When thus alloyed, it forms a metal closely resembling 
silver, in which form it is known as block-tin, britannia, etc. 
When mixed with copper in different proportions, it forms 
the metals known as bronze, bell-metal, and speculum- 
metal. When tin-foil is coated with quicksilver, it forms 
a reflecting surface for mirrors. 

Tin must have been one of the earliest metals known, 
as it enters into the composition of bronze, of which most 
of the metallic weapons and tools of the ancients were made. 

Bi-noxide, or stannic oxide, is the only pure tin ore of 
any importance. In composition, it contains seventy-eight 


174 


THE TEACHER’S AID. 


parts of tin and twenty-two parts of oxygen, and is usually 
called tinstone. 

Tin ore is of various colors, including gray, white, differ¬ 
ent shades of yellow T , red and black. In some places the 
tin ore occurs in veins which run through granite and slate 
rock, or else scattered throughout their mass. 

Some tinstone is obtained directly from the veins, or 
lodes, and is known as mine-tin; other kinds are obtained 
by washing the alluvial deposits in which the tin ore is 
found, and are known as stream-tin. 

Some ores are found that contain almost an equal amount 
of tin and copper; in such a case, it is difficult to determine 
whether they could be classed as tin or copper ores. 

The preparation of tin obtained from the mines, is a very 
difficult operation, and requires much time and labor, 
owing to the fact that the tin is so thoroughly mixed with 
the other ingredients with which it is found. It is neces¬ 
sary that it should be stamped, or ground to a very fine 
powder, before the particles of tin can be thoroughly sepa¬ 
rated; this is accomplished by means of washing with 
water. 

The powdered ore is abundantly supplied with water, 
which passes through the ore into a grating adjoining the 
stamps; the water conveys the powdered metal into a 
channel, where there are two pits. 

The pure and heavier portions fall into the first pit, 
and are called the crop, the remainder passes through the 
first, and is deposited in the second pit, where it is known 
as the leavings. 

The ore undergoes repeated washings in order to sep¬ 
arate as thoroughly as possible all impurities from it. 
And for this purpose a machine known as the bundle is 
generally used. 

The ore, and earthy matter in the form of thick mud, 


THE TEACHER'S AID. 


175 


are carried by means of square pipes or channels and de¬ 
posited on tables. Here, by the use of water, the metallic 
substance is separated from the lighter, stony impurities; 
the impurities are carried away, and the tin ore only re¬ 
mains. 

The purified tin ore, thus obtained, has next to be 
deprived of its sulphate and arsenic; this is accomplished 
in a reverberatory furnace, where the ore is smelted and 
run into a cast iron pan, from which it is ladled into moulds 
of a convenient size, and when cooled is formed into ingots. 

The peculiarly remarkable properties of tin, and in par¬ 
ticular its malleability, its brilliancy, and the slowness 
with which it oxidizes at the ordinary temperature, renders 
it of great use in the arts and in manufacturing. 

Articles made of tin retain their brilliancy much longer 
than those made of silver, and require only about one-sixth 
as much cleaning and polishing as the silver articles re¬ 
quire, in order to look bright, and clean. 

Tin is very largely used in the coating of other metals, 
as iron and copper; especially thin sheet-iron to be used 
as tin plate. Tin-foil is used for various purposes, the 
most important being as a reflecting surface for mirrors, 
and for wrappings and coatings for articles in which the 
moisture is desired to be retained, as tobacco, yeast, etc. 
A coating of tin will prevent iron from becoming rusty. 

Tin is a very light metal, and is not affected by contact 
with air or water, but readily fuses by the action of heat, 
and is affected by strong acids. It is a very important and 
valuable metal for manufactiung purposes; and, although 
extensively used, it is quite inexpensive. 

Note: Remarks on cost, uses, manufacture, etc., of tin. 


176 


THE TEACHER'S AID. 


GELATINE. 

Gelatine is the term applied to a concrete, animal sub¬ 
stance, but also properly belonging to glue, and isinglass; 
vegetable jelly is very similar to this substance. 

Gelatine, and glue, are the more or less pure and care¬ 
fully prepared jelly of mammals; but the term isinglass 
is exclusively applied to certain gelatinous parts of fishes, 
which, from the great amount of gelatine they contain, 
are usually merely dried, and used without any further 
preparations, other than dividing them into smaller par¬ 
ticles, in order to facilitate their action. 

Gelatine is a thick, elastic, transparent, adhesive, yel¬ 
lowish-white substance; it is soluble in either hot or cold 
water, but more so in hot water. 

Gelatine for commercial purposes is prepared from a 
variety of animal substances, but chiefly from the softer 
parts of the hides of oxen, cows, calves, and sheep; also 
from the bones, hoofs, and other parts of animals. 

In the manufacture of gelatine, the materials used are 
carefully washed, cleaned, and cut into small pieces and 
placed in a weak solution of caustic soda, where they are 
allowed to remain for a week or ten days, during which 
time the solution is kept warm by means of steam pipes. 

When the operation has been carried on for a sufficient 
length of time, the pieces of skins, etc., are removed and 
placed in an air-tight vessel, which is lined with cement; the 
compound is kept here for a short time, which is determined 
by the skill of the manufacturer, and the materials used. 

After this operation, the pieces are placed in a revolving 
cylinder, which is supplied with an abundance of clean, 
cold water, and when thoroughly cleaned they are placed 
in another vessel which is lined with wood, in which, by 
the action of the fumes of burning sulphur, they are purified 


THE TEACHER’S AID. 


177 


and bleached. They are given a final washing in clean, 
cold water, which removes the sulphurous acid. 

They are next squeezed as dry as possible, and placed 
in the gelatizing pots; these pots are large, earthen vessels, 
which are enclosed in steam-tight wooden cases. Water 
is poured into these vessels with the prepared pieces, and 
raised to a high temperature by the application of heat 
in the cases enclosing the pots. 

By this means the gelatine accumulates, and while still 
hot it is strained off and poured out in thin layers, which 
soon become cool, and solidify; they are then cut into 
plates, usually of an oblong shape, and placed in nets to dry. 

There are other processes for obtaining gelatine, but they 
are all very similar, and the results are about the same. 
Different grades of gelatine are made, according to the 
quality of the materials used. 

The French are most successful in the manufacture of 
superior gelatines. They make their plates extremely thin, 
which imparts a greater transparency, and seeming freedom 
from color; they also color it most beautiful colors, and 
make it into very fine rolled sheets, which give it an appear¬ 
ance of great purity and delicacy. 

The purity of gelatine may be determined by sub¬ 
jecting it to a small quantity of boiling water, and if pure, 
it will form a thick, colorless solution, devoid of smell; if 
made of impure materials, it will be of a yellow, gluey con¬ 
sistency, and emit an offensive odor. 

Gelatine is used in the manufacture of glue, and for 
many manufacturing purposes, as in the preparation of a 
substance for stiffening cotton and linen goods; in the 
manufacture of straw goods, etc. 

It is manufactured extensively, and is a very important 
industry. 

Remarks on cost, uses, manufacture, etc., of gelatine. 



178 


THE TEACHER'S AID. 


GLUTEN. 

Gluten is a tough, elastic substance, obtained from the 
flour of wheat and other grains. It is of a grayish-white 
color, and when dried by exposure to the air, becomes 
brown and brittle. It is obtained by forming a paste of 
any of the cereal grains, with water, which forms a taste¬ 
less mass or substance, known as gluten. 

This paste is placed in a bag made of linen or cotton, 
and kneaded or agitated in water. At first it imparts a 
milky appearance to the water, but the kneading is con¬ 
tinued, and the water changed until it ceases to be dis¬ 
colored. 

The substance remaining in the bag constitutes the 
gluten, and usually contains particles of starch, bran, and 
oily matter, which have not been removed by the water. 
Gluten contributes much to the nutritiousness of flour, and 
gives tenacity to its paste, which quality generally fits it 
for conversion into bread. 

The gluten yielded by wheat and rye flour is much more 
tenacious than that made from corn, oats, and other 
grains. When moist, and in a close place, or vessel, it 
rapidly becomes sour, and acquires a disagreeable smell; 
but when exposed to sufficient air and heat, it readily 
becomes dry, and forms a hard, horny-looking mass of a 
brownish color. 

The glutinous portions contained in food constitute a 
very nutritious, fattening and strengthening ingredient. 

Remarks on the cost, uses, etc., of gluten. 


^ & ** 


THE TEACHER'S AID. 


179 


GUTTA PERCHA. 

Gutta percha is the dried milky juice of a species of tree 
found in Malay and the adjacent islands. These trees 
attain a thickness of from two to three feet, and the wood, 
being very soft, is of little value. 

To obtain the gutta percha, the choicest trees are se¬ 
lected and felled. Between the bark and the wood of the 
tree there is a deposit of milky juice. The bark is removed 
and the juice collected. 

This juice hardens when exposed to the air, and when 
collected is kneaded and worked as it hardens, and is made 
into cakes which form the gutta percha. Further prepara¬ 
tions are necessary before it is fit for use. And for this 
purpose the cakes or lumps into which it has been formed 
are sliced into very small, thin shavings, and placed in a 
tearing machine which revolves in a tank of hot water. 
This process reduces the shavings to very small pieces, 
which are washed free of all impurities, such as particles of 
bark, etc. 

It is necessary that all such impurities should be re¬ 
moved in order that the gutta percha may be smooth and 
compact, as its quality and value depend upon its purity 
and texture. 

When sufficiently cleaned it is worked into masses, which 
are then rolled several times between hot cylinders for the 
purpose of expelling any air or water which it may contain. 
This process makes it of a uniform texture. 

It is next formed into sheets of various thickness by 
being passed between heated steel rollers, or it is formed 
into rods, pipes, speaking-tubes, etc. 

In color it is of a light reddish-brown or flesh color. Its 
uses are various, being employed in the manufacture of 
both useful and ornamental articles. 


180 


THE TEACHER’S AID. 


It is used as handles for knives, surgical instruments, 
etc. It is the material from which golf balls are made, 
and it is used by dentists as fillings for teeth. 

Another very important use is made of gutta percha in 
the coating of telegraph wires, as it is an excellent non¬ 
conductor. 

Gutta percha cloth is often used as a substitute for oiled 
silk. It does not stand the heat or wear as well, and is not 
as flexible; but it is far less expensive, costing only about 
one-half the price of oiled silk. 

In appearance it closely resembles India rubber and 
some varieties of wood. Gutta percha is only very slightly 
elastic. 

Remarks on cost, uses, etc., of gutta percha. 

WILLOW. 

The willow of commerce is obtained from a tree or shrub, 
of which there are many species. These trees or shrubs are 
mostly natives of the colder temperate regions, although 
some are found in warm countries. 

They are mostly shrubs of a very humble growth; one 
variety, found in the mountains of Scotland, seldom attains 
more than an inch or so above the ground. 

Those which more generally receive the name of willow 
are trees of a larger size and a very rapid growth. The 
wood of many of them, although light and soft, is very 
durable and is used for many purposes. Willow was used 
in ancient times for making shields. This wood, being 
tough, wears better than other kinds, and on this account 
is used for making paddles for boats. 

Willow trees are planted for ornamental purposes, 
.especially the weeping willow; they are planted for fences 


THE TEACHER'S AID. 


181 


and on the banks of streams to prevent the water from 
washing away the banks, their fibrous root-work being a 
prevention for this. 

They grow very rapidly from cuttings when planted in 
a moist soil. The twigs of most willows are very tough, 
flexible and durable, and are used by gardeners and coopers 
and in the manufacture of chairs, baskets and many other 
forms of wicker-work. 

The wood makes good fuel when dry. In some coun¬ 
tries the leaves and young shoots are used for food for 
cattle, being dried and stored for that purpose. 

Remarks on willow-work, cost, uses, etc. 


PARCHMENT. 

Parchment is the skins of animals, which have been 
prepared for writing upon. In early times it was the chief 
material for writing on and was used as early as five hun¬ 
dred years B. C. Its manufacture spread all over Europe, 
and it remained in use until the invention of paper from 
rags. 

Parchment is made from the skins of sheep and goats. 
The ordinary writing parchment being made from those of 
old sheep and goats, while the finer kind, called vellum, is 
made from the skins of young calves, lambs and kids. The 
thick, common kind, used for drumheads, tambourines, 
battle-doors, etc., is made from old goat-skins, and in the 
northern part of Europe from wolf skins. It was formerly 
used as a tablet for writing upon, as black lead could easily 
be erased by moisture. 

In preparing parchment, the treatment is much the 
same as in dressing skins for leather. The skins are put 
into a lime-pit, where they remain until the hairs are easily 



182 


THE TEACHER'S AID. 


removed. They are then smoothly and equally stretched on 
a frame, and the fleshy side is curried until perfectly smooth. 

This side is then dressed by sprinkling powdered chalk 
and lime over it. The other side is treated to a grinding 
or rubbing with a flat pumice stone, after which it is 
allowed to dry, still tightly stretched on the frame. 

The process of drying is very important and must be 
conducted slowly, and for this reason must be carried on in 
the shade to prevent drawing or wrinkling. This opera¬ 
tion often has to be repeated many times in order to insure 
a good quality and a uniform smoothness. 

Much depends on the quality of pumice stone used and 
the skill with which it is applied. When finally quite dry 
the chalk and lime are removed by rubbing with a lamb 
skin which still has the wool on. 

Aside from the animal parchment there is another variety 
known as vegetable parchment, which resembles the former 
so closely that it is difficult to distinguish them apart. 

Vegetable parchment is made from the water-leaf, or from 
unsized paper, by placing it for a few seconds in a solution 
of oil of vitriol, diluted with one-half of its amount of water. 

For successful results, care must be taken that the solu¬ 
tion contains the proper proportion of water and vitriol, 
The diluted acid must be allowed to cool to the ordinary 
temperature before being used. Without proper attention 
to these two points the operation will prove a failure. 

In some respects vegetable parchment is more desirable 
than the animal, as it is less liable to be destroyed by insects. 
It can also be made much thinner and can be used for trac¬ 
ing paper and is not injured by moisture. 

The process of manufacture was slow, and in consequence 
paper has supplanted the use of parchment and vellum. 

Remarks on the early uses of parchment and vellum, 
cost, etc. 


THE TEACHER'S AID. 


183 


PAPER. 

Paper is a fabric composed of various vegetable and 
some animal substances. Among the substances used in 
the manufacture of paper the most important are asbestos, 
aloe, bark of various kinds of trees, bean stalks, sugar cane, 
cocoa nut fibre, cotton, clover, flax, weeds, grasses, hay, 
husks of grain, hops, hemp, heath, jute leaves, moss, 
manilla, turf, roots of various kinds, sawdust, various kinds 
of wood, thistle doAvn, straw, tobacco stalks and any kind 
of old paper and rags. 

Of the animal products used the chief ones are wool, 
silk, leather, fur and hair. The processes of manufacturing 
paper from any of the above articles have been patented 
by each inventor. But whatever the material used, the 
process for all is nearly the same. 

The substances used have to be reduced to a fine pulp 
by the use of water. The pulping is facilitated by boil¬ 
ing the materials in a strong lye or caustic alkali. This 
process thoroughly cleanses the materials, and softens and 
separates all vegetable fibre very readily. 

This compound is then put into a machine which washes 
away all dirt and everything except the pure vegetable 
fibre. This machine is supplied with a continual flow of 
pure water, and the discolored water readily escapes 
through a fine gauze screen. 

After this process of washing is completed the material 
is placed in a large chest to drain. When the water has 
drained away the compound is placed in the bleaching-vats 
and submitted to the action of a very strong solution of 
chloride of lime for about twenty-four hours, being fre¬ 
quently stirred during this time. 

When the bleaching process is completed it is then put 
into a hydraulic press, where the greater portion of the 


184 


THE TEACHER’S AID. 


water and the chloride of lime is removed. It is then 
placed in another washing machine, where it is agitated 
for an hour in clean water. 

This last washing removes all traces of the bleaching 
material. It is then put into the beating engine, where the 
fibres are separated with great rapidity. This process 
takes from five to six hours, at the end of which time the 
material and the water are worked into an impalpable 
pulp. 

This pulp is then let out into a vat, where it is kept in 
constant agitation, and from this pulp-vat the hand or 
machine workmen are supplied. 

Paper was originally made by hand, but the hand 
process is little used at this date. In the hand process the 
pulp was placed in a mould, consisting of a wire screen 
attached to frames. The water in the pulp readily drains 
off through the wire gauze, and after it has stood in an 
inclined position for a few minutes the sheet of pulp is 
applied to a piece of flannel cloth stretched on a board. 
And when slight pressure is applied the pulp will leave 
the board and adhere to the cloth. The pulp or paper is 
then pressed, dried, sized, tinted, folded and made up into 
quires. 

Paper machines have been brought to such a state of 
perfection that paper can be made very rapidly. It can be 
made in a continuous web of any desired length, and before 
leaving the machine is sized, dried, calendered, hot-pressed 
and cut into sheets. 

Machine-made papers are usually sized and tinted in 
the pulp state, although in some papers the coloring is 
applied to the surface. Paper can be ruled, figured, etc., 
in any pattern desired. 

Remarks on the different kinds of paper, appearance, 
uses, values, quality, etc. 


THE TEACHER’S AID. 


185 


PORCELAIN. 

Porcelain is a very fine variety of earthenware. It was 
originally manufactured in China and Japan, but it is now 
universally made in all civilized countries. 

All earthenwares that are white, semi-transparent and 
flinty are called porcelain; but they differ greatly in fine¬ 
ness, quality and beauty. 

The porcelain of China is composed essentially of two 
substances known as kaolin and petuntse. Petuntse is 
easily fused, but kaolin does not fuse with the same degree 
of heat. The materials used in porcelain are only semi- 
vitrified ; that is, only one substance is vitrified, the other 
is not. 

Porcelain is usually a hard substance, but it can be made 
in a soft, plastic state, in which form it can be moulded into 
small figures and ornamental objects. In the soft state it is 
employed by sculptors and in the manufacture of vases, etc. 

In the manufacture of porcelain, the purest clays and 
calcined flints are used. These materials are ground fine in 
separate mills, water being freely used in the operation. 

The ingredients are then mixed, and, by the use of water, 
are formed into a soft, plastic mass. This compound is 
made so thin that it can be run into moulds of the desired 
size and shape. 

The moulds used are made of plaster of Paris, and, being 
porous, they soon absorb the moisture in the paste, and 
cause it to dry rapidly. 

Articles made of porcelain are either moulded or cast, 
and sometimes both means are employed before the article 
is completed. 

When the porcelain objects are moulded they are placed 
on shelves in a drying-stove, where they are subjected to a 
slow, steady heat until they become thoroughly dry. They 




186 


THE TEACHER'S AID. 


are next placed in a burning-kiln, where the process of 
drying and hardening is completed. 

The drying kiln is supplied with a series of furnaces, 
usually eight in number. The dishes, or other objects to be 
fired, are placed in large earthen vessels prepared for the 
purpose, where they are prevented from touching each 
other by means of the insertion of small pieces of burnt clay 
between them. By this ingenious arrangement, the heat 
penetrates equally the entire surface of all the pieces at 
the same time, uniformly affecting them all. 

When these earthenware vessels have been sufficiently 
filled with the dry, unfired porcelain objects, they are placed 
in the kiln, the central xDortion of which is left vacant; in 
this way, each earthenware vessel constitutes a small oven 
in which several pieces of porcelain are baked at once. 

When the kiln has been filled, fires are kindled in all the 
furnaces, the fuel employed usually being coal. Great care 
must be taken to select the very best quality of coal, as 
impurities and sulphurous vapors might injure the entire 
contents of the kiln, thereby causing great loss of money, 
time and labor. 

The process of baking, or firing, requires great care, 
attention and skill. Any neglect on the part of the operator 
now would entail great loss. 

The process of baking lasts from forty to forty-two 
hours, after which the fire is allowed to die and the kiln to 
become gradually cool. 

The kiln is then opened, and the articles removed; but 
care must be taken not to open it until perfectly cool, as 
sudden contact of the cold air from the outside with the 
heated objects in the kiln might cause them to break. 

The porcelain objects are next glazed by being dipped 
into a vessel of moulten liquid, which is made by fusing 
glass, flint, cullet, and white lead, in different proportions. 


THE TEACHER'S AID. 


187 


The porous porcelain readily absorbs the hot, liquid 
glaze, and the articles are again placed in the kiln and fired. 
The heat of the kiln melts the glaze, and changes it into a 
clear, perfectly transparent glass coating, which entirely 
covers the surface of the object. 

In the decoration of porcelain, the colorings and gildings 
are invariably applied over the glaze, while in pottery the 
objects are decorated, lettered, etc., before being glazed. 

Porcelain is chiefly employed in the manufacture of 
dishes, ornaments, vases, and the like. Objects made of 
porcelain are often decorated by being painted in different 
colors and designs. 

Some pieces of porcelain that have been decorated by 
famous artists are very valuable. There are some very 
rare and valuable porcelain objects of early manufacture, 
while many very pretty and artistic designs of recent 
manufacture are very cheap. 

Remarks on cost, uses, manufacture, etc., of porcelain. 

& & 

SORGHUM. 

Durra, Sweet Sorghum, Sorgo Grass, and Chinese Sugar 
Cane, are all names applied to what is known as sorghum. 
It is a genus of the grass family, of which there are many 
species. 

Sorgho grass is a native of the East Indies, but it is 
extensively cultivated in Asia, Africa, Southern Europe, 
the United States, and to a limited extent in England and 
Germany. In the two latter named countries its cultiva¬ 
tion is not a success, as the climate does not permit it to 
reach perfect development. 

Although sorghum is a native of warm countries, it 
flourishes in this country as far north as Maine; it is, how- 





188 


THE TEACHER'S AID. 


ever, more extensively cultivated in the Southern states, as 
the length of the warm season gives it more time to mature. 
Its cultivation has become a leading and profitable industry 
in the South. 

The common sorghum, or that specie which is grown in 
the colder Northern states, is an annual, and is propagated 
by means of the seeds which it produces. It grows to a 
height of from five to ten feet; the leaves are ribbon-like, 
from two to five feet long, with a strong middle vein, and 
shaped like a blade of grass. They are smooth on the 
upper surface, and rough underneath; in color they vary 
from a light to a dark green. In fact, the plant is very 
similar to the common Indian corn. 

The top of the stalk is ornamented with spikelets of 
bloom, clustered in ample panicles, which are at first green, 
but turn to russet brown when ripe. The stalk is jointed, 
hollow, and filled with a juicy pulp. 

The seeds which these spikelets produce are small, round, 
and hard. In some countries they are ground into flour 
and used as food. But the bread made of this flour is not 
very good. The seeds, leaves and stalk make excellent 
food for cattle; and for this purpose they are largely used. 
This plant matures in four or five months. 

The sugar cane cultivated in the Southern plantations, 
is propagated by means of cuttings, the upper top joint 
being used for this purpose. 

The cuttings are planted in rows which are three or four 
feet apart, the plants being placed two feet apart. When 
planted in a rich soil, and having the benefit of a good 
climate, it will attain a height of twenty feet; but the usual 
height is six feet. 

When the canes are fully ripe they are stripped of their 
leaves and cut off a short distance above the ground; they 
are tied in bundles, in which form they are ready for the mill. 


THE TEACHER’S AID. 


189 


The plant “stools” like wheat, and new sprouts soon 
spring up and take the place of the original stalk, and for 
this reason the planting does not have to be renewed for 
several years. The first canes produced are the largest, 
and the succeeding ones gradually decrease in size. 

In the United States the chief uses to which sorghum 
and sugar cane are applied are in the manufacture of sugar 
and molasses; these products are obtained from the juice 
of the plant by means of expression and evaporation by 
heat. In India the outer part of the stems is used for 
thatching, for making mats, screens, doors, fences, etc., 
and in Bengal the small, hollow stems are used as pens. 

The process of obtaining sugar and molasses from cane 
consists in abstracting the juice from the cane by means of 
a press. It is next strained in order to free it from all 
chaff, pith and impurities, and then boiled in huge kettles. 

When it has boiled and evaporated to a certain con¬ 
sistency it is in the form of molasses; but for sugar it re¬ 
quires longer boiling and more care. 

The sugar, before being completed, goes through several 
complicated processes of clarifying, graining, etc., before it 
is ready for the market. 

Remarks on the cultivation, etc., of sorghum. 

^ 

TALLOW. 

Tallow is an animal fat, procured chiefly from animals 
of the ox and sheep kind; it is usually spoken of as beef 
and mutton tallow. 

This variety of fat is found chiefly located about the 
kidneys and intestines of the animal. The corresponding 
fat of swine is called lard, and that of the bear is known as 
bear’s grease. 



190 


THE TEACHER’S AID. 


The qualities possessed by tallow make it particularly 
well adapted for the manufacture of candles, and for this 
purpose it is extensively used. 

Candles were the chief means of illumination until the 
first quarter of the nineteenth century; but owing to the 
improvements made in methods of illumination, the tallow 
candle has gone into disuse, being superceded by petro¬ 
leum, gas and electric light. 

Tallow has always been used in the manufacture of 
soaps, but for the better grades it is now being replaced by 
the use of palm and cocoa-nut oil. 

It is employed as a lubricant for machinery and as an 
application to iron as a preventative against rust. Large 
quantities of tallow are produced and used annually. It is 
a very inexpensive article. 

Among the tallow-producing countries may be men¬ 
tioned North America, South America, Russia and India. 

Mineral tallow is a mineral substance which closely 
resembles animal tallow; it is of a yellowish-white color, 
soft and flexible, and very much like wax or tallow. It is 
flaky like spermaceti, and devoid of smell; it melts readily. 

Vegetable tallow is the product of several different kinds 
of trees. It is a thick, oily, resinous substance, very much 
like animal tallow, and capable of being made into candles. 

The tallow tree of Malabar is very large, with leathery 
leaves that attain a length of from four to ten feet. The 
flowers, which are white, are five-petaled, very fragrant, 
and grow in large panicles. The stem or body of this tree 
often attains a circumference of sixteen feet. 

The tallow is obtained by boiling the seeds, which yield 
a fine white vegetable tallow. This tallow, having no 
unpleasant smell, is suitable for the manufacture of soap 
and candles, for which it is largely employed. 

In the tallow tree of China the seed capsules are divided 


THE TEACHER'S AID. 


191 


into three cells, which contain seeds of an almost hem¬ 
ispherical shape; these seeds are covered with a beautiful 
white tallow. 

The Chinese collect these capsules and crush them and 
the seeds together; the crushed mass is then boiled and the 
fat skimmed off while still hot. When skimmed and puri¬ 
fied, it is mixed with wax in order to give it a better con¬ 
sistency, the proportion usually being ten parts of the 
vegetable tallow to three parts of wax. The candles pro¬ 
duced from this mixture are beautifully white. 

The tallow tree has been introduced into North America 
and is cultivated in the vicinity of Charlestown and Savan¬ 
nah, and has become almost naturalized in the mountainous 
parts of Carolina. At the beginning of winter the leaves 
become bright red, and the pericarps fall off, leaving the 
white seeds suspended by minute threads, which gives the 
tree a very remarkable and beautiful appearance. 

Remarks on the cost, uses, production, etc., of tallow. 

^ j* S 

HIDE. 

Hide, or pelt, is the skin of an animal, separated from 
the body. It may be either raw or dressed; but the term 
hide is usually applied to the undressed skin of the larger 
domestic animals, as the ox, horse, etc. 

When hides are tanned they are used in the manufacture 
of boots, shoes, saddles, harness, straps, furniture covering, 
book-bindings, useful, ornamental and valuable articles. 

In the preparation of hides for manufacturing purposes 
they are subjected to the process known as tanning. (See 
preparation of leather.) 

The commercial value of hides depends on the kind and 
quality, some kinds being expensive, while others are very 





192 


THE TEACHERS AID. 


cheap. They form a very important and leading article in 
the commercial world, and are made use of at all seasons of 
the year and in all parts of the world. 

Remarks on cost, uses, etc., of hides. 

& & 

DELF. 

Delf, or delft, is an earthenware which was invented 
about the year 1450. It is manufactured in much the 
same way as china and porcelain, the chief difference being 
that coarser clays, etc., are used. 

It is employed in the manufacture of dishes, etc., and is 
a very important and useful article. Objects made of delf 
are much cheaper than those made of porcelain and china. 

Remarks on cost, uses, etc., of delf. See manufacture 
of china and porcelain. 

jt j* 

CHINA. 

China, or chinaware, is a delicate, thin, semi-transparent 
earthenware made from a certain variety of clay. It is 
manufactured chiefly in China, from which it received the 
name; it is also known as porcelain. 

The ingredients used are kaolin, flint, glass, etc.; they 
must be as pure as possible in order to obtain a china of 
good texture and clearness. 

These ingredients are ground into very fine powder by 
the use of mills. They are then thoroughly incorporated 
with each other, and by the use of water are formed into a 
soft, liquid paste. 

This paste, while yet soft, is poured into moulds of the 
desired size and shape, where it soon solidifies. The 


THE TEACHER’S AID. 


193 


moulded objects are then placed in a drying oven and per¬ 
mitted to stand, heat being gradually applied until all the 
moisture has evaporated and the articles have become hard. 

They are next placed in the kiln or drying oven, which is 
heated by means of several furnaces; here the heat is ap¬ 
plied and the temperature gradually raised. 

This process is continued for at least forty hours, when 
the fire is gradually cooled off and the baked objects re¬ 
moved from the kiln. 

They are now complete in form and perfectly hard, but 
are rough and porous and require to be glazed. This is 
accomplished by dipping each article in a vat of molten 
liquid made of melted glass, slag, etc. The moulten liquid 
forms a smooth, uniform coating over the entire surface of 
the article, which renders it incapable of absorbing moisture 
and less liable to become soiled by exposure and handling. 

Objects made of china may be painted, lettered, 
stamped, decorated, etc., either before or after glazing; 
but it is usually done before. Many very beautiful and 
artistic designs are wrought on china, and some of the very 
oldest pieces of decorated china are quite valuable. 

Dresden china is considered the most valuable, but it is 
often so closely imitated that inexperienced persons who 
are making a collection of china are often induced to buy 
this bogus china with the belief that it is the real china of 
an early manufacture and therefore considered valuable. 

Dresden china manufactured prior to 1814 commands 
the highest prices; and that made between 1715 and 1770 
is considered the very best, as the production of that period 
was of very fine quality and commands high prices. 

China is chiefly used in the manufacture of dishes, vases, 
urns, etc. Articles made of pure china of a fine grade are 
very expensive. 

Remarks on cost, uses, manufacture, etc., of china. 

13 


194 


THE TEACHER'S AID. 


GUM ARABIC. 

Gum arabic is a production obtained from the stems of 
acacia arabica and acacia vera, two leguminous trees which 
are natives of Africa and some parts of Asia. 

Gum arabic is a hard, flinty, semi-transparent substance, 
varying in color from a light straw, through the different 
shades of yellow and yellowish-brown, to garnet. 

It dissolves in either cold or warm water, but more 
readily in warm. When dissolved it forms a glue, or 
mucilage, which is more or less thick, according to the 
amount of water used in combination with it. 

Gum arabic is extensively employed in the manufacture 
of textile fabrics in order to impart to them the desired 
stiffness; it is also used in the manufacture of straw goods 
for the same purpose. 

It forms an important ingredient in the manufacture of 
mucilage and glue. 

Remarks on cost, uses, etc., of gum arabic. 

j* 

VERDIGRIS. 

The substance known as verdigris is properly the rust of 
copper. It is formed by any fruit pulp, or skins, being left 
on copper. The skins of grapes are especially useful in 
producing verdigris. 

In manufacturing it in any quantity, copper plates are 
covered with fermenting grape • skins and are placed in 
layers. After a few weeks a crust of greenish hue forms on 
the copper plates and is scraped off and made into a thick 
paste with vinegar, and moulded. It is bluish-green in 
color, very tough and not easily pulverized. 

This salt is more readily obtained by wrapping the 


THE TEACHER'S AID. 


195 


plates or sheets of copper in cloths wet with vinegar and 
allowing them to remain for a time. 

Verdigris is a poison, but when properly used is a medi¬ 
cine in such cases as ulcers, ulcerated sore throat, and in 
the removal of warts. It is applied with a small brush to 
the effected parts. 

A great many cases of poisoning occur from food being 
cooked in copper-lined vessels; but if the vessel is clean; 
and the food removed at once when cooked, there is little 
danger of poison. 

But if foods, especially of an acidy nature, are cooked 
and left to cool in copper vessels, there is great danger of 
poisoning on account of the acid uniting with the copper 
and forming verdigris. 

Pickles are made a fine green color by putting copper 
coins in the vinegar, or by allowing them to remain in a 
copper kettle with vinegar over them. When treated this 
way they are unfit for food. 

Remarks on uses, cost, poisonous effects, etc., of ver¬ 
digris. 

CANDY. 

Candy is the name applied to sugar when converted into 
confectionery by the aid of water and heat. Other ingre¬ 
dients are usually added, such as extracts, fruits, nuts and 
coloring matter. 

The process usually consists of dissolving the sugar in 
water and then placing it on the fire, where it is gradually 
brought to the boiling point. After boiling the required 
time, of which the candy-maker must be the judge, it is 
removed from the fire, and the flavoring and coloring 
added. 

If it is to be a fruit or a nut candy, the fruits or nuts are 


196 


THE TEACHER’S AID. 


dipped into the hot syrup and placed on tins to cool. For 
the other kinds of candy the syrup is poured into moulds of 
the desired shape and size, or the syrup is taken into the 
hands as it gradually becomes stiff, and pulled or drawn, 
usually over a hook for this purpose, until it becomes stiff 
and hard. It is then cut, twisted or formed into different 
designs. 

There are a great many varieties of candy, some of 
which are very expensive and some very cheap grades, 
owing to the quality of material used and the skill and 
time required in making. 

Some of the coloring materials, particularly those for 
the very bright colors, are poisonous, and therefore very 
injurious when eaten in quantities. 

Candy-making forms a very important and profitable 
industry and gives employment to many people. 

Remarks on making, uses, cost, etc., of candy. 

& 

GLYCERINE. 

Glycerine is a liquid substance, or oil, which forms the 
basis of fatty matter. It is a transparent, colorless liquid, 
of a slippery consistency and devoid of smell. It is the 
product of various processes of the decomposition of animal 
matter. 

When the animal matters are saponified or treated with 
potash; oxide of lead or soda, or exposed to the influence of 
heat and steam, the fatty acid separates and becomes 
glycerine. 

Glycerine is found ready formed in a few fats and in all 
fermenting liquors, amounting to about three per cent of 
the fermented sugar which they contain. 

Glycerine is extensively used in medicine, being em- 


THE TEACHER'S AID. 


197 


ployed in the treatment of skin diseases; it is also used 
internally and as a solvent in the preparation of many 
drugs. It is often used as a preservative in anatomy and 
in the keeping of meats; it is used in the process of the 
printing or stamping of calicos, in the dressing and prepa¬ 
ration of leather, and in the manufacture of perfumes. 

Great quantities of glycerine are used in the preparation 
of nitro-glycerine, dynamite and other explosives; it forms 
an important ingredient in the manufacture of copying-ink, 
and it is an excellent lubricating oil for all kinds of machin¬ 
ery, etc. 

Remarks on cost, uses, etc., of glycerine. 

% 

4 1 

VINEGAR, 

« 

Vinegar is an acid liquid, obtained by the fermentation 
of vegetable substances. It is made from wine, beer, malt, 
etc., which have become sour. These fluids are diluted 
with water, and after becoming properly fermented are 
distilled. A quantity of yeast is often added to hasten 
fermentation. 

A very good vinegar is produced by adding yeast to a 
quantity of sweetened water. This is allowed to become 
sufficiently sour, when it is drawn off and is then put in 
casks or barrels, and a quantity of resin and crude tartar 
is added. 

Vinegar is also made from molasses and water, in a 
similar way. Cider vinegar is made by diluting cider that 
has become sour, or fermented, with water, and the per¬ 
mitting it to stand until perfectly soured. It can also be 
made from the pure cider without dilution; in this way it 
requires a much longer time, but produces a much superior 
quality of vinegar. 


198 


THE TEACHER'S AID. 


Vinegar of an inferior quality is made from the “vin¬ 
egar plant” (or mother), which is a product of any very 
strong vinegar. It is a thick, scum-like substance, clear and 
partially transparent, and forms on the surface of the fluid. 

If a piece of this “ mother ” is put into sweetened water 
it readily sets up fermentation and converts the water into 
vinegar. Cold tea, fruit juices and many other things are 
frequently converted into vinegar. 

Beech shavings are used in clarifying vinegar, as the 
impurities readily settle upon them, leaving the liquid 
clear, in which condition it sours more readily. 

Vinegars vary in color and acidity according to the dif¬ 
ferent materials from which they are produced. 

For culinary purposes vinegar is used in sauces, for 
pickling, preserving, etc. It is used medicinally in many 
ways and is an antidote in cases of alkali poisoning; it is 
used hot as an application to sprains, bruises and pains, 
and gives great relief; it is used as a cooling beverage to 
allay thirst and is a relief in cases of hiccoughs and in cases 
where lime has entered the eye, an application of vinegar 
will allay the pain and fever and give relief. 

Remarks on cost, uses, etc., of vinegar. 

j!> & 

ZINC. 

Zinc is a hard, bluish-white metal of a lustrous appear¬ 
ance externally. At ordinary temperature it is rather 
brittle, but when heated becomes perfectly ductile and 
malleable and can be drawn out into thin wire or beaten 
into very thin plates. 

This metal is never found in the native state. There are 
several varieties of zinc ore, but the only two of importance 
are blende and calamine. 


THE TEACHER'S AID. 


199 


Blende, black-jack, or sulphuret of zinc, when pure, 
contains about sixty-seven per cent of zinc, but, like most 
ores, is seldom found pure. It occurs in all the older 
geological formations and is often found in the ores of 
copper and tin, but most frequently found occurring in the 
veins of lead ore. 

Blende crystallizes and exhibits considerable brilliancy, 
but the lustre is of a waxy appearance, rather than metallic. It 
is usually of a dark color, owing to the sulphuret of iron which 
it contains, and for this reason the miners call it “black jack.” 

Calamine, or carbonate of zinc, contains fifty-two per 
cent of zinc when pure, but it varies much in the amount 
of metal it contains, on account of impurities. It forms in 
crystals, but more frequently occurs in masses, and is 
usually of a dull yellow or reddish-brown color. 

There are several distinct processes for the extraction of 
zinc from its ore, but the most common process is as fol¬ 
lows : The zinc ore is crushed between rollers to the size of 
hazel nuts and then roasted in a calcining furnace for about 
twelve hours, being stirred occasionally during the process. 

The furnace in which the roasted ore is reduced is very 
much like a glass furnace. In shape it is either circular or 
octagonal and contains six pots or crucibles about three 
feet high and two and a half feet at their widest part. 

These pots are made of fire-clay, and in the bottom of 
each there is an opening from which a sheet-iron tube 
descends about eight feet. Under the open end of each 
tube a sheet-iron vessel is placed to receive the condensed 
zinc. The pots are filled with the prepared calcined ore, 
mixed with the proper amount of ground coke. The 
covers are now adjusted and fastened on. 

The descending pipe has been previously fixed to the 
bottom of the pot, and the opening in the pot plugged with 
wood, which becomes converted into charcoal by the action 


200 


THE TEACHER’S AID. 


of the heat, and is then sufficiently porous to allow the zinc 
vapor to pass and at the same time stops the descent of 
the coke and the ore. 

The heat of the furnace is raised and soon produces vapor 
of zinc in the pots. This vapor is condensed as it descends 
through the pipes, and drops into the vessels placed at the 
bottom of the pipes to receive it. 

It requires about three days to work off a charge in the 
pots, and great care must be taken and the pots closely 
watched, as any leakage generally causes much loss of zinc. 
The rough zinc is removed from the vessels, where it has 
collected in lumps, and is melted in cast-iron pots, where it 
is well stirred, skimmed and finally cast into ingots or cakes 
of the ordinary commercial size. The skimmings are again 
put in with a new charge of ore. 

As zinc is so easily rolled into sheets, it is used for roof¬ 
ing, baths, water-tanks, spouting, etc.; also for covering the 
bottoms of ships, for name-plates, for engraving upon, and 
for galvanic batteries. As a material for casting artistic 
works, zinc possesses the combined properties of having a 
low melting point and of taking sharp impressions from the 
mould, so as to require little labor from the chasers. 

It possesses considerable hardness, and on this account 
has become a favorite and useful material for making casts 
for statues, statuettes and different kinds of ornaments. 

Zinc has been used successfully as a coating for sheet- 
iron, for roofing and other purposes, and also for the coating 
of iron wire, especially telegraph wire. When applied to 
the surface of other metals it protects them from rusting. 

Oxide of zinc is used to a great extent as a white pig¬ 
ment and also as an ingredient in pottery colors. Several 
of the compounds of zinc are used medicinally. 

Remarks on the cost, uses, color, weight, etc., of zinc, 
and where obtained. 


THE TEACHER’S AID 


201 


HORN. 

Horn is a hard substance or appendage growing on the 
heads of certain animals. They serve the animal as 
weapons, both of offense and defense. The horns of differ¬ 
ent animals project to various lengths and terminate in a 
point. In form they are bent, curved, branched or spiral. 

Horn is a gelatinous substance and can easily be con¬ 
verted into jelly. It consists of gelatine, albumen and 
sulphate of lime. Deer horn possesses the same property 
as bone, only that the proportion of cartilage is greater. 

Horn can be softened by the application of heat and 
water, when it can be split into very thin layers. These 
layers can be flattened by putting them between smooth, 
heated iron plates, and placed in a press. 

A solid sheet may be made by placing the edges together 
between polished copper plates and these tightly screwed 
together by a vise and placed in boiling water for some 
time and then removed and plunged in cold water. 

By this process the edges are smoothly and firmly 
united, and in this way all small pieces of horn may be 
utilized. When heated, horn can also be pressed into a 
die or mould and made into any desired shape, which it 
retains when allowed to cool in the mould. 

In color, horn varies from almost white to yellow, gray, 
red, brown and black. It can be dyed almost any color by 
the use of any of the common dyes, but the mineral dyes 
give it a more permanent color. 

By skillful management it can be made to very closely 
resemble the costly tortoise-shell. 

Horn is used for making handles for knives, forks, um¬ 
brellas, etc.; for making ornamental boxes, hairpins, buckles 
and various other ornaments. Combs are made from the 
flattened sheets of horn, and from the solid parts of the 


202 


THE TEACHER'S AID. 


buffalo horn beautiful carvings are made. Beautiful 
drinking cups and powder horns are made from the ox 
horn. Articles of ornamental furniture are made from the 
deer horn. 

Some kinds of horn are more expensive than others. 
The horn-producing countries are South America, the East 
Indies, Germany and some others, which export large 
quantities of horn to other countries, to be used for manu¬ 
facturing purposes. 

Note: Remarks on the value, uses, cost, etc., of horn. 

jt & 

WOOL. 

The word wool generally signifies the fleecy coat of the 
sheep, which constitutes a very essential material for cloth¬ 
ing in all cold and temperate climates. 

Wool is the most important of all animal substances used 
in manufactures, and ranks next to cotton as a raw material 
for textile fabrics. 

Wool is composed of very fine particles or hairs of a 
wavy or kinky nature, and this quality readily enables 
them to adhere to one another when being twisted and 
made into threads. If the hairs or fibres were straight 
they would not twist together so readily, and the fabric 
produced would not be so strong or serviceable. 

Wool varies in quality according to the particular breed 
of sheep from which it is obtained. The nature of the 
climate, food, shelter and soil also affect the quality and 
the quantity of wool produced. 

In a wool having a first-grade quality the fibres are fine, 
soft, elastic, sound and of a good color, and free from all 
detrimental and annoying impurities; and the commercial 


THE TEACHER'S AID. 


203 


value of wool therefore depends upon the extent to which 
it possesses these qualities. 

There are two classes of sheep, known as the long-wooled 
and the short-wooled. The wool of young sheep is con¬ 
sidered of more value and better quality than that produced 
by older sheep. 

Goat’s wool is made use of in much the same way as 
sheep’s. The wool of the angora goat is very valuable; it 
is a white, silky wool, averaging from five to six inches in 
length. 

In the manufacture of cloth from wool, silk and cotton 
are often mixed with the wool. The silk and woolen mix¬ 
tures being higher-priced than the all-wool, while the cot¬ 
ton and woolen mixtures make a cheaper article. Many 
beautiful and durable combinations are made with these 
mixtures. 

Note: Uses and values of wool. Shearing, scouring, 
carding, spinning, dyeing, etc. 

TILE. 

Tile are hollow, cylindrical tubes of baked clay of vari¬ 
ous sizes, and used for draining wet, swampy land, and for 
carrying off surface water. Any common clay will make 
the ordinary tile of commerce. 

In the manufacture of tile the clay is put into a wooden 
hopper, called the mill. It is moistened with water and 
then ground fine and smooth. When of a consistency to 
be properly moulded, it passes from the mill into moulds 
that are attached to it. 

These moulds vary in size and are adjusted to the mill 
so as to produce the size of tile desired. As the soft clay 
passes out of the mould in the desired shape and size, it is 


204 


THE TEACHER’S AID. 


cut in lengths, usually a foot in length, by a thin, strong 
wire, worked by a lever, in the hands of the operator. When 
cut, they are picked up and placed on a cart. And the 
rapidity with which they are cut, placed on the cart and 
followed by succeeding ones keeps the operator in constant 
motion. 

In case a tile passes through the mould in a misshapen 
condition, is cracked or broken by the operator, as is fre¬ 
quently the case, it is cast back into the mill, ground up 
and re-moulded with the other clay. 

The newly moulded tile are placed on end on shelves in 
the drying sheds, where they are left to dry and harden. 
To facilitate the process and lose no time in the operation, 
the drying-sheds are fitted with heating pipes. Heat is 
turned on, and the moist tile soon become dry and hard. 
At this stage they are of a dirty gray color. When suf¬ 
ficiently dry they are ready for the process known as firing 
or burning. 

For this purpose a kiln has been built. It is made of 
brick and mortar. Fire brick being more durable, they are 
generally used in the construction of the kiln. This kiln is 
circular in form, hollow, and has no openings except a small 
door and six or eight small openings called fire-holes, situ¬ 
ated at regular intervals around the base. 

The tile is wheeled from the drying-sheds and arranged 
in the kiln. The smaller sizes are placed within the larger 
ones in order that no space may be wasted. When com¬ 
pletely filled the door is closed and fastened and remains 
thus until the process of burning and cooling has been 
completed. 

Fire is then introduced into the fire-holes, and the 
process of firing or burning has commenced. Coal is the 
fuel used, although wood answers the same purpose. 

From the time the firing is commenced it has to be con- 


THE TEACHER'S AID. 


205 


tinued day and night until the process is completed. Fuel 
has to be added at regular intervals, and the fire kept 
raked bright and clean. 

Any carelessness on the part of the operator in charge 
might entail great loss, for on the proper burning depends 
the entire value of the tile, and a little neglect or misman¬ 
agement now might spoil the contents of the kiln and thus 
entail the loss of many hundred dollars and a great amount 
of labor. 

The heat and smoke pass upward through the tile, the 
smoke passing off through a flue at the top of the kiln. 
When the process of burning has continued for the required 
time the fire is then raked away and allowed to cool. 

But the kiln is not opened immediately, as the contact 
with cold air would break the heated tile. After the fire 
has been removed and sufficient time allowed for the tile 
to become somewhat cooled, the door is opened, and they 
are removed. It is often removed while it is hot enough to 
burn the hands, and those working among the hot tile and 
heated air in the kiln are often obliged to go out into the 
open air. 

The tile, which is now a bright reddish color, is very 
hard and has a clear metallic ring. When removed from 
the kiln it is stacked in piles of assorted sizes and is now 
ready for the market. 

The kiln is immediately filled with tile from the drying- 
sheds, which in their turn are kept filled from the moulding 
and grinding machines, and thus the process continues 
with no change or cessation. 

Tile is also a name given to plates of baked clay of vari¬ 
ous shapes and used for different purposes. It is used for 
roofing buildings, for floors, hearths, mantles, stairs, pave¬ 
ments, etc. 

The finer kinds of paving tile are known as encaustic 



206 


THE TEACHER'S AID. 


tile. The smaller pieces of burnt clay, stone, glass, etc., 
called tile, are used for mosaic purposes. They are colored 
different colors and shades. Artistic and very pretty 
designs for ornamental purposes are made with these tiles. 

Note: Remarks on uses, cost, manufacture, etc., of 
tile. 

& & 

JUTE. 

The jute of commerce is a fibre produced from two 
plants alike in qualities, though very different in appear¬ 
ance. One kind has round seed-pods and reddish stalks, 
the other having long seed-pods and bright green stalks. 

The jute fibre is the cheapest known fibre, and from it 
are made gunnies, gunny-cloth and cordage, from the 
coarser preparations, and from the finer qualities shirting, 
coat-linings, carpets, mattings, etc. 

It is extensively used in mixing with silk, cotton and 
woolen fabrics, and from this mixture is made a finer cloth, 
used in the manufacture of curtains, table-cloths and dress- 
goods. 

In many of the articles made of the prepared jute fabric, 
the yarn is used in its natural color, as in gunny-bags, etc.; 
but for finer fabrics it is bleached, and when used for car¬ 
pets, mattings, etc., it is dyed various colors. 

The jute fabric, when mixed with cotton, silk and wool, 
makes a much finer fabric than when all jute. Jute has 
been extensively used in the manufacture of paper from a 
very early date. 

Although indigenous to the tropics, the plant grows in 
any climate and on all kinds of soil, rich alluvial lands, and 
lands subject to salt water tidal influence particularly fav¬ 
oring its production. It is a very exhaustive crop on the soil. 

The plant, if weeded once, requires no more attention 


i 


THE TEACHER’S AID. 


207 


until time for cutting. It grows to the height of twelve 
feet, having a single stalk without branches or leaves till 
near the top. It will grow and flourish, although inundated 
with water for a month at a time. 

Bengal is the largest jute-growing country, and from 
there, jute in large quantities is exported to America, France 
Austria, Italy, England and many other countries, where 
it is then manufactured into the required articles. Ready 
manufactured jute articles are exported from Bengal. 

In Bengal the plant is cut while in bloom, about three 
months after sowing. It is cut close to the ground, and 
the leaves and branches removed, and then soaked in water 
from ten to twenty days. The water rots the outer bark, 
&nd the fibre is loosened. It is then beaten till nothing but 
the fibre remains. This fibre is then cleaned and made into 
“ drums ” of seventy or eighty pounds. Great importance 
is attached to the length and strength of the fibre. 

If intended for the export market it is pressed into bales 
of three hundred pounds or more. Fine jute possesses a 
beautiful, glossy, golden appearance, and is soft and silky 
to the touch. 

The cultivation of jute has been tried in England, but 
has not proved remunerative. It has been very success¬ 
fully grown in small quantities in America. 

The gunnies, gunny-bags and sheeting made from jute 
are used for packing various kinds of merchandise. 

Remarks on cost, uses, cultivation, etc., of jute. 

VITRIOL. 

Vitriol is a glass-like salt, or sulphate, obtained from 
different metals. There are several varieties of vitriol, 
differing in color and appearance, and derived from differ- 





208 


THE TEACHER'S AID. 


ent sources. The different varieties are known as green 
vitriol, blue vitriol, red vitriol and white vitriol. 

Green vitriol, or copperas, is a sulphate of iron and is 
obtained by the solution of iron in diluted sulphuric acid, 
from which the salt is condensed by evaporation into clear 
bluish-green crystals containing a portion of water. 

Red vitriol is a red sulphide of iron and is obtained by 
direct union of two elements at a high temperature or by 
precipitation of a proto salt of iron by ammonia. It is in 
the form of glistening masses, varying in color from a 
grayish-yellow to a reddish-brown or red. 

Blue vitriol is a sulphide of copper obtained by dissolving 
the black oxide of copper in a solution of sulphuric acid, 
and allowing the salt to crystallize out. These crystals are 
large, of a blue color, insoluble in water, and are exten¬ 
sively used in dyeing calico peculiar shades of blue and 
green; also as an ingredient in the manufacture of ink. 

White vitriol is a solution of zinc and is composed of 
white, glistening crystals. It occurs as a residue in the 
process of obtaining hydrogen from sulphuric acid and zinc; 
also from burning zinc blend or sulphide of zinc, which, 
when heated in air, resolves into sulphate. 

Oil of vitriol is sulphuric acid, which is obtained by the 
distillation of green sulphate of iron or by the oxidation of 
sulphurous acids with other acids. 

Sulphuric acid is very strong and will destroy wood, 
cloth, cork, etc., and is injurious to the skin and eyes if 
permitted to come in contact with them, and requires to be 
handled with great care. 

Vitriol is a strong poison, but is at the same time a very 
useful medicine. It is largely used in the arts and in 
manufacturing. 

Remarks on injurious effects of vitriol. Other uses, 
cost, etc. 


THE TEACHER'S AID. 


209 


SPONGE. 

Sponge is a genus of the family spongidea. The sponge 
is a creature of very low organization, and controversies 
were long waged as to whether it should be regarded as 
belonging to the vegetable or animal kingdoms. It was 
finally assigned to the animal kingdom, but it was uncer¬ 
tain what position it should occupy in the group. 

The living sponge is composed of an exceedingly soft, 
pulpy substance and hard parts, which this substance 
secretes. Water is admitted through numerous small 
pores, which open into a system of branching canals, and 
these lead to the large pores we see on the surface, and 
through which the water and other substances are dis¬ 
charged. 

Sponges are common in ponds and lakes, as well as in 
nearly all parts of the sea, and their forms are exceedingly 
varied and often very beautiful. Some cover the rocks 
like a carpet of moss; others grow in massive clusters; 
others branch like trees and shrubs, and others take the 
forms of the most beautiful cups, vases, goblets, etc., while 
others are top-shaped, conical, cylindrical and thread¬ 
shaped. Some varieties are simple, and others are corn- 
compound or branched. 

Sponges secrete hard parts, which form the well-known 
“sponge” of commerce. In a living state many sponges 
exhibit bright colors, owing to the presence of coloring 
matter. 

The sponges employed for domestic purposes derive 
their value from the elasticity and compressibility of their 
fibrous framework. The sponge of commerce is found in 
the seas of many warm climates. Some small species live 
at a great depth. 

* Sponges are collected by diving. The diver takes down 

14 


210 


THE TEACHER'S AID. 


with him a flat piece of stone with a hole drilled through it. 
To this a cord is attached, and the diver uses this as a guide 
in searching for the desired spot. When he has reached 
the growing sponges he tears them from the rocks, and, 
placing them under his arms, gives the signal, by pulling 
the rope, for his assistants in the boat to draw him up. 

In some places the sponges are secured by tearing them 
from the rocks by means of a fork, or hook, at the end of a 
long pole; but the sponges thus collected are torn and 
damaged and sell at a low price. 

When the sponge is brought to the surface it is a fleshy- 
looking substance covered with a firm skin, whose openings 
appear and disappear at intervals. When the diver cuts 
into it the interior looks like raw meat, with numerous 
canals and cavities. 

The first thing to be done after the sponge has been 
brought to the surface is to remove the flesh, and this must 
be done at once, since otherwise putrefaction would set in, 
which would destroy the elasticity. This leaves merely 
the skeleton of the animal, which has to be further cleaned 
before it is ready for the market. 

To destroy the animal matter and prepare the sponges 
for market, they are buried for several days in the sand 
and then thoroughly washed. They are bleached, dried 
and sorted, and are now ready for the various uses to which 
they are applied. 

The sponge of commerce is of a light yellowish color, is 
very light in weight, and in feel resembles a piece of coarse, 
dry cloth; but when wet it swells up and becomes quite 
soft and pliable. 

The mortality rate among the divers is high, from one 
hundred and fifty to two hundred dying each season in a 
total of six hundred employed. Only the most desperate 
men are willing to undertake the task, they being for the 


THE TEACHER'S AID. 


211 


most part escaped convicts, criminals and fugitives from 
justice. They are paid from $400 to $1,200 each for a 
season of seven months, which is about ten times the usual 
wages in Tripoli; but in spite of this the difficulty of secur¬ 
ing sufficient men for the work is growing. 

Sponges that are secured at the risk of life are the best 
that are known, and are such as are used by surgeons in 
delicate operations. They are found in varying degrees of 
fineness along the shores of the Mediterranean, the posses¬ 
sions of Turkey being the best field, while the Spanish, 
French and Italian coasts are devoid of them. 

They grow at all depths, from two to two hundred 
fathoms, and as the work of gathering them has continued 
it has become necessary to dive deeper for them. They 
do not grow rapidly; an ordinary bath sponge, measuring 
about a foot in diameter, is ten years old. 

While the Florida sponges are not worth over eighty 
cents per pound in average value, the Turkey sponge is 
sometimes worth as much as fifty dollars per pound. It is 
thought possible that some of the best foreign sponges from 
Tripoli might be transplanted in Florida waters and form a 
nucleus from which a large area might be raised. The dif¬ 
ficulties of transportation would be great, however, for the 
sponge, although he does not look like it, is a very delicate 
animal and does not stand long journeys well. The United 
States Fisheries Commission, however, has been considering 
the advisibility of making the experiment. 

The uses to which sponges are applied are numerous 
and varied. They are used in surgical operations for 
removing blood and in stopping hemorrhages; they are 
used as an accessory to the bath, and burnt sponge was 
once a valuable remedy for the goiter. In the school room 
the sponge is ever a welcome guest. 

Remarks on appearance, size, value, etc., of sponges. 



212 


THE TEACHER'S AID. 


TURPENTINE. 

Turpentine is a semi-solid resin, which is yielded by 
various species of pine and by some other trees when 
incisions are cut in them. 

The chief varieties of turpentine are common turpentine, 
Bordeau turpentine, Venice turpentine and China turpen¬ 
tine. The Venice turpentine, which is regarded as the 
best variety, occurs as a clear, transparent, pale yellow, 
viscous mass, of a balsamic odor and acrid, bitter taste; it 
is perfectly soluble in spirits of wine and increases its den¬ 
sity when exposed to the air. 

On distilling it with water, it yields a considerable quan¬ 
tity of essential oil, commonly known as spirits of turpen¬ 
tine. This oil of turpentine is colorless, transparent, has a 
strong, refractive power, a strong, peculiar odor, and a 
disagreeable, acrid taste. 

It is soluble in alcohol, in ether and the fixed and essen¬ 
tial oils, but is insoluble in water, on which it floats. 

It is a good solvent for many substances, among which 
may be especially mentioned sulphur, phosphorus, caout¬ 
chouc and the varieties of resin, and it is largely used in 
many departments of the arts, forming a large proportion 
of all oil paints. 

Great quantities of turpentine are exported into Britain 
from the United States, where it is chiefly obtained from 
the swamp pine. 

Oil of turpentine is used to a large extent in medicine, 
although, from its disagreeable taste and odor and from 
certain bad effects which it occasionally produces, it is 
often supplanted by less certain remedies. 

When turpentine is distilled with water the oil comes 
off, and the residue, which is left in the bottom, constitutes 
what is known as common resin. 


THE TEACHER'S AID. 


213 


Medicinally it is used in the compounding of liniments. 
It is used by artists and painters to reduce the paint to the 
desired consistency, and also to assist in the process of 
drying. 

Note: Remarks on cost, uses, production, etc., of tur¬ 
pentine. 

& t 

MAJOLICA. 

Majolica is a name given at first by the Italians to a 
certain kind of earthenware, because the first specimen 
they saw came from Majorca. 

It is used in the manufacture of pottery, dishes, vases, 
urns, etc. It is a light-weight material and is usually col¬ 
ored or tinted very bright and beautiful colors. It is also 
stamped in pretty designs and figures. 

It is not as durable as ironstone china or delph. Some 
of the most artistic articles made of majolica are very 
expensive. 

Note: Remarks on cost, uses, etc., of majolica. 

£ 

MACE. 

Mace is the aril of the nutmeg, or the second coat that 
covers the nutmeg. It is a thin, membraneous substance, 
of an oily nature and yellowish color, composed of flakes 
divided into many ramifications. It is a spice and is 
extremely fragrant and aromatic. 

In the fruit it is situated within the fleshy part and 
envelops the nutmeg. This membrane is blood-red and 
somewhat fleshy when fresh. 

It is prepared for the market by drying for some days in 
the sun and flattening. It has a peculiar, strong, agreeable 


214 


THE TEACHER’S AID. 


smell and taste, and contains a clear, yellowish, volatile oil 
and a red, buttery, fixed oil. 

The volatile oil is obtained by distillation, and the 
buttery oil by expression. When the buttery oil is mixed 
with the volatile oil and other substances it is known as 
nutmeg balsam. 

Mace is used as a spice and has much the same flavor as 
the nutmeg. It is imported chiefly from Penang and 
Singapore, where it is received from the spice islands. 
Small quantities are received from the West Indies, where 
its cultivation receives some attention. 

Note: Remarks on cost, uses, etc., of mace. 


POTASH. 

The chief source of this important article of commerce 
is from the vast quantity of wood cut down in Canada and 
burned in the clearing of forests for cultivation, and also 
from the branches of trees felled for the timber. 

The ashes, mixed with a small quantity of quick lime, 
are kept in large wooden cisterns and covered with water. 
This mixture of ashes and water is well stirred and allowed 
to settle; the next day the clear liquid is drawn off and 
evaporated to dryness in iron pots, whence it is called pot¬ 
ash. 

When a sufficient quantity is produced to fill a cask of 
five hundred weight it is fused at a red heat and poured 
into the cask. The mass, when cold, is colored gray ex- 
ternalfy, but when broken shows a pinkish tint internally. 
It is very deliquescent, and consequently the casks require 
to be nearly air-tight. 

In this state potash contains large quantities of foreign 
materials, amounting to about forty per cent, among which 


THE TEACHER’S AID. 


215 


sulphur and carbonaceous matter predominate. In this form 
it constitutes the crude American potash of commerce. 

If it is calcined by a reverberatory furnace, the sulphur 
is driven off and the carbonaceous matter burned out; the 
carbonic acid, however, combines with the potash and 
forms it into a carbonate. 

To form it into pearl-ash it is then broken up and dis¬ 
solved in water in a wooden cistern having a perforated 
bottom covered with straw, through which it filters, and is 
afterwards evaporated in flat-bottomed iron pans. 

As it approaches dryness, it is stirred with iron rods, 
which break it up into round, lumpy masses of a pearty- 
white color, and in this state it is the pearl-ash of com¬ 
merce and contains about fifty per cent of pure potassa. 

All land plants yield potassa when burned, many yield¬ 
ing it in much greater proportion than the timber trees of 
North America; but the circumstances under which the 
materials are obtained give an advantage to our manu¬ 
facture which hitherto has been able to compete with the 
world in the production of this article. 

The uses to which potash is applied are in the prepara¬ 
tion of other compounds of potash and in the preparation 
of soaps and glass; it is employed largely in medicine for 
making effervescent draughts, Dover’s powders and chlor¬ 
ide of potassium. 

It is also used in the manufacture of lucifer matches, as 
a bleaching agent, in the finer operations of metallurgy, as 
a remedy for the poisonous bites of insects, reptiles, mad 
dogs, etc. It is used in destroying warts, fungoid growths 
and other similar things, for the cure of many diseases, 
such as stomach and kidney trouble, epilepsy, dropsy, 
rheumatism and many kinds of skin diseases. 

Note: Remarks on cost, uses, etc., of potash and its 
compounds. 



216 


THE TEACHER’S AID. 


POISON. 

Poison is a substance that is capable of destroying life. 
It may be considered to be divided into three classes, 
according to their mode of action upon the system, viz.: 
Irritants , narcotics and narcotic-irritants. 

The irritants, when taken in ordinary doses, speedily 
occasion intense vomiting and severe abdominal pains. 
They act chiefly on the stomach and intestines, which they 
irritate, inflame and frequently corrode, and may thus 
occasion ulceration, perforation or gangrene. 

Amongst those which possess corrosive properties are 
strong mineral acids, caustic alkalis, corrosive sublimate, 
etc., while among the pure irritants which exert, no chem¬ 
ical action on the tissues with which they come in contact, 
may be mentioned arsenic, cantharides, carbonate of lead, etc. 

The narcotics act specially on the brain and spinal cord. 
Among their most common symptoms are giddiness, head¬ 
ache, obscurity of sight or double vision, stupor, loss of the 
power of the voluntary muscles, convulsions and finally 
complete coma. 

Under the head of irritant poisons may be included: 

First, mineral acids, sulphuric, nitric and hydrochloric 
acids; vegetable acids and other salts, as oxalic acid, binox- 
alate of potash and tartaric acid; the alkalis, as pearl-ash, 
soap-lees and ammonia; the metallic compounds, as white 
arsenic, yellow arsenic, corrosive sublimate, acetate of 
lead, carbonate of lead, sulphate of copper, arsenite of 
copper, tartarized antimony, chloride of zinc, chloride of 
antimony, nitrate of silver, sulphate of iron and bicarbon¬ 
ate of potash. 

Second, vegetable substances, namely, colocynth and 
gamboge in large doses, savin, croton oil, the leaves and 
flowers of the common elder. 


THE TEACHER'S AID . 


217 


Third, animal substances, such as cantharides, to which 
must be added the occasional cases in which sancages and 
certain fish and molluscs, usually quite inocuous, act as 
irritant poisons. 

The narcotic poisons include opium, hydrocyanic acids, 
oil of bitter almonds, cyanide of potassium, henbane, alcohol, 
ether, chloral and chloroform, while narcotic-irritant poisons 
include nux vomica, meadow saffron, white hellebore, fox¬ 
glove, common hemlock, water hemlock, fool’s parsley, 
thorn-apple, monk’s hood or woolf’s bane, deadly night 
shade, tobacco, Indian tobacco, the bark and seed of the 
common laburnum, the berries and leaves of the yew-tree 
and certain kinds of fungi. 

In point of law, the use of poison to kill or injure any 
person or certain animals renders the poisoner amenable to 
the criminal courts. Restrictions are made to the sale of 
many of the most injurious of poisons. 

Some of these poisons are very expensive, while others 
cost but a trifle. In the manufacture of many of these 
poisons great care must be taken in order that those hand¬ 
ling them may not receive injurious effects. 

Note: Remarks on the cost, uses, effects, manufacture, 
etc., of the various kinds of poison. 

jt & 

PEWTER. 

Pewter is a common and very useful alloy of the metals, 
tin and lead. There are two other kinds of pewter, which 
have a more compound character. 

Common or ley-pewter consists of four parts of tin and 
one part of lead; plate-pewter is made of one hundred parts 
of tin, eight parts of antimony, two parts each of bismuth 



218 


THE TEACHER’S AID . 


and copper; another kind, called trifle, is composed of 
eighty-three parts of tin and seventeen parts of antimony. 

Although these are the standard formulas, each kind is 
often varied and adulterated to suit the purposes of the 
manufacturer. The chief alteration usually being the 
addition of a large portion of lead. 

Pewter is used for making small articles, such as spoons, 
etc., and as coating over metal articles. It is a soft metal 
and can be easily pounded or hammered; it melts readily 
and is susceptible of a good polish, but soon becomes dull 
when exposed or handled very much. It is not a very 
expensive metal. 

Note: Remarks on cost, uses, etc., of pewter. 

PUTTY. 

Putty is a composition of whiting and drying oil worked 
into a thick paste. It is used by painters and glaziers; by 
the painter for filling up holes in surfaces prior to their 
being painted with oil colors, and by the glazier for fixing 
panes of glass in windows, etc. It becomes remarkably 
hard in time and fixes the glass immovably. 

It is of a grayish-yellow color and becomes quite hard 
when exposed to the air. 

Note: Remarks on uses, cost, etc., of putty. 

LEAD. 

Lead is a bluish-white metal of considerable brilliancy. 
This brilliancy soon disappears when exposed to the air, 
owing to the formation of a thin film of oxide. 

It is so soft that it can be easily cut with a knife or made 


THE TEACHER'S AID. 


219 


to readily take impressions, and when applied to paper it 
leaves a dark or discolored mark. 

It may be cut or beaten into thin sheets, but in ductility 
and tenacity it is very low in the scale of metals. Pure 
lead is of very rare occurrence. 

To obtain the pure lead for manufacturing purposes the 
lead ore is melted in furnaces and cleaned from all impuri¬ 
ties. Lead is an important metal in the arts. 

Rolled out into sheets it is largely used for roofing 
houses, for water cisterns and for water-pipes. It is also of 
great use in the construction of large vessels, for the manu¬ 
facture of sulphuric acid and in the manufacture of shot 
and bullets. Its value in the manufacture of shot, etc., is 
well known. 

Alloyed with antimony, etc., it is largely consumed for 
type-metal, and when combined with tin it produces solder. 
A great amount of lead is required for the manufacture of 
pewter, Britannia metal, etc. 

White lead is a substance extensively used as white paint 
and also to form the body of other colors in painting. 
Minimum red lead is much consumed in the manufacture of 
flint-glass and porcelain, and to some extent as a pigment. 

Another very important use for lead is in the manufac¬ 
ture of lead-pencils. 

Note: Remarks on the use, cost, production, etc., of 
lead. 

^ & 

MARBLE. 

Marble, in its strict and proper sense, is a rock crystal¬ 
lized in a saccharine manner, having the fracture of loaf 
sugar and composed of carbonate of lime; it is either almost 
pure when the color is white, or when combined with the 
oxides of iron or other impurities it is of various colors. 



220 


THE TEACHER'S AID. 


But many other kinds of stone are popularly included 
under the title “ marble.” Indeed, any limestone rock suf¬ 
ficiently compact to admit of a polish is called marble. 

Saccharine or marble is a white, fine-grained rock, 
resembling loaf sugar in color and texture, working freely 
in every direction, not liable to split, and susceptible of a 
high polish. 

Of the marbles used by the ancients, the most famous is 
Parian marble, a finely granular and very durable stone 
with a waxy appearance when polished. Some of the finest 
Grecian sculptures were made of this marble. 

Of colored marbles the best are Rosso antico, a deep 
blood-red sprinkled with minute white dots; Verde antico, 
a clouded green produced by a mixture of white marble 
and green serpentine; Giallo antico, a deep yellow, with 
black or yellow rings, and Nero antico, a deep black marble. 

Some varieties of marble are very durable and stand the 
test of time and the elements for years without being in the 
least affected, while other varieties are readily affected by 
the elements and soon crumble away. 

Marble is used for monuments, shafts, columns, vaults, 
sculpture, floors, ornamental purposes, etc. Some of the 
finer varieties are quite expensive, while others are inex¬ 
pensive. Many of the varieties of marble exhibit the most 
beautiful forms of the rock creation. 

Note: Remarks on cost, uses, production, dressing and 
polishing of marble. 

£ & 

EIDER-DOWN. 

Eider-down is the down that is obtained from the eider 
duck. About a half a pound of down is said to be obtained 
from each of the nests annually. But when this half-pound 


THE TEACHER’S AID. 


221 


has been thoroughly cleaned it is reduced to about a quarter 
of a pound. 

The nest of the eider duck is made of fine sea-weeds, dry 
twigs and mosses, when they can be procured, closely mat¬ 
ted together. The eggs are deposited without any down, 
but as the process of incubation proceeds the female strips 
the down of her breast and places it around them. By 
this means they are kept warm at any time she may leave 
them; but it would seem that the down is indispensable to 
the hatching of the eggs, for if the eggs and down are 
removed a second time so that the female cannot afford a 
further supply for the protection of the eggs, the male con¬ 
tributes the down of his breast for the third set of eggs. 

The common practice in Norway and Iceland is to take 
away the eggs twice, leaving the third set to increase the 
species. The elasticity of eider-down is so great that three- 
fourths of an ounce of it, when loose, will fill a large hat, 
but when compressed two or three pounds may be made 
into a ball and held in the hand. 

The down taken from the nests of the birds is much 
better than the down taken from the bodies of dead birds. 
That taken from the nests is known as live down, and that 
taken from the dead birds is called dead down. 

These fowls are natives of cold countries, being found in 
the northern part of Europe and North America, in Nor¬ 
way, Sweden, Iceland and Greenland; they usually avoid 
-warm or even temperate climates. Great numbers breed 
on the coast of Labrador and more northern parts of North 
America, where, formerly, little attention has been paid to 
the collection of the down. 

In Iceland, Norway and most other countries the breed¬ 
ing grounds of these ducks are most carefully taken care of 
and protected, and pass from father to son as most valuable 
inheritances. 



222 


THE TEACHER'S AID. 


Cattle are very frequently removed from the islands 
these birds inhabit, and a strenuous effort is made to keep 
dogs and wild animals from disturbing the birds. 

The eggs of these birds, which are usually five in num¬ 
ber, but sometimes six or seven, are about three inches 
long and fully two inches wide, and are of a pale green 
color. They are not protected by down when first depos¬ 
ited in the nest, but as the process of incubation advances 
the mother strips the down from her breast and covers the 
eggs with it. 

In Norway and Iceland the birds show so little fear that 
they will permit people to approach near enough to touch 
them as they sit on their nests. In these breeding grounds 
the nests are sometimes placed so closely together that it is 
almost impossible to walk among them without stepping 
upon them. 

Near the capital of Iceland there is a valuable breeding 
ground, in which the nests of these fowls are found in 
almost every little hollow place in the rocks. These birds 
will also readily take possession of holes that are cut for 
them in rows on the sloping hill-sides. The interior of old 
buildings ,old stone walls, etc., are often made use of, for the 
same purpose. 

Eider-down is extensively used in Iceland, Germany and 
other countries for lining or stuffing bed-covers, which, in 
those countries, serve in place of blankets. 

The eider-duck can be domesticated where it has free 
access to the sea, but this is very rarely done. The flesh of 
these birds is fairly good, but becomes greatly improved 
when domesticated or partially so and when farinaceous 
food is mixed in large quantities with their ordinary diet of 
crustaceans and mollusc. 

Eider-down is used in the manufacture of clothing and 
for millinery purposes, for beds and bed-covers, and for 


THE TEACHER'S AID. 


22 


O 

o 


many other purposes. The genuine eider-down is quite 
expensive, but it is often mixed with other downs, and in 
this way a cheaper and an inferior down is produced and sold 
as eider-down. This down is usually used in the natural 
white color, but it can be colored any desired color or shade. 

Note: Remarks on cost, uses, etc., of eider-down. 

j* & 

ARROW-ROOT. 

Arrow-root is the name applied to the starch extracted 
from the root of the different species of maranta. The 
Indians were supposed to have used the root of one variety 
to remove the poison inflicted by arrows. The juice of 
some species has been recommended as an antidote for 
poison and as a cure for the stings and bites of venomous 
insects and reptiles. The name arrow-root came presum¬ 
ably from the use the Indians made of it to remove the 
poisonous effects of arrows. 

The arrow-root of commerce is obtained from one 
variety known as the starch-plant, and from other varieties 
a nutritious medical food is obtained. 

The best arrow-root is obtained from the tuberous 
roots, or rootstalk of a plant which grows abundantly, 
and which is also cultivated in the West Indies. The 
roots are about a foot in length and vary in thickness 
from a half inch to an inch and a half; in color they 
are almost white; they are jointed and covered with 
large, paper-like scales. They sometimes grow in a curved 
form with the ends projecting above the ground, and from 
these projections new plants are produced. 

The plants grow to the height of two feet and have ovate- 
lanceolate leaves of a hairy texture; the flowers are small 
and grow in clusters on two flowered stalks; the fruit is 
round and about the size of a currant. 



224 


THE TEACHER’S AID. 


In the preparation of the product the roots are gathered 
when about a year old, and after being carefully washed 
and peeled they are reduced to a pulp. This is done in 
some countries by means of a mill prepared for that pur¬ 
pose, while in other places it is done by beating. 

The pulp is then washed in clean water, which process 
removes all the starch. It is again washed and allowed to 
settle, after which the water is drained off and the starch 
dried in the sun or in drying-houses prepared for this pur¬ 
pose; while drying, the starch is protected from the dust 
and insects by the use of gauze covering. Owing to the 
acid contained in the roots, the knives used in peeling and 
the shovels used in lifting are made of German silver. 

Arrow-root is of much value as an article of food, and is 
used and recommended for invalids and children. In its 
preparation as an article of diet it is simply dissolved in 
boiling water, sweetened to suit, and flavored with some 
agreeable juice or extract. In combination with milk it is 
made into custards, puddings, etc. 

When the arrow-root or starch has been obtained it is in 
the form of a light, opaque powder; it is packed in tin cases, 
boxes or barrels and carefully closed; in this form it is now 
ready for the market. It is sometimes adulterated by the 
use of corn, rice, potato and wheat-starch, which makes it 
inferior in quality. 

Arrow-root is a product of tropical countries only, from 
whence it is exported to the colder climates, where large 
quantities are consumed annually. 

The chief arrow-root producing countries are the West 
Indies, the East Indies, some of the countries of South 
America, Africa and Bermuda. 

Note: Remarks on cost, uses, production, manufac¬ 
ture, etc., of arrow-root. 


THE TEACHER'S AID. 


225 


SILVER. 

Silver is a metal of a brilliant white color and possessing 
the metallic lustre to a remarkable degree; it is susceptible 
of a high polish and gives out a clear, sweet, ringing sound 
when struck. It is extremely malleable, and its ductility 
is only a little less than that of gold. 

It is harder and more elastic than gold, but possesses 
these qualities in a less degree than iron, copper and plati¬ 
num. It is very dense and heavy, a single cubic foot of sil¬ 
ver weighing about six hundred pounds. 

Silver is a good conductor of both heat and electricity, 
and is not affected by atmospheric moisture at any tem¬ 
perature. It is not affected by cold, but melts when sub¬ 
jected to a great amount of heat. Neither hot nor cold 
water has any apparent effect on it, but it is readily acted 
upon by some of the stronger acids. 

Silver does not rust or become oxidized, but will fre¬ 
quently tarnish by continual exposure to the air on account 
of the formation of films of sulphides of silver. 

Silver is found in the native state in many parts of the 
world. It occurs in thin plates or leaves, in fine threads, 
in the form of cubes and octahedrons, or in fibrous masses. 
It also occurs in combination with lead, gold, antimony, 
sulphur, mercury and arsenic. 

Silver is obtained from surface ores or from veins which 
are a short distance from the surface; it is also obtained 
from shafts and mines that extend many feet, sometimes 
hundreds, below the surface of the earth. 

In the reduction of silver ores the process is accom¬ 
plished by the use of mercury, which has a strong attrac¬ 
tion for silver, and thus separates it from the other ingre¬ 
dients. 


15 



226 


THE TEACHER'S AID. 


By another process the separation of the silver is effected 
by the solubility of chloride in a solution of common salt, 
after which it separates when cold. 

The easiest and most common method of separating the 
silver from the other ingredients is by means of smelting in 
a furnace; this method is generally applied to the richest 
ores only. 

For smelting, the ores are crushed and then mixed with 
some form of lead, old slag and a quantity of iron-ore and 
lime. The mixture is then subjected to heat in a charcoal 
furnace, which brings down the silver and lead, combined 
as an alloy. 

These two metals are then separated in a cuppellation 
furnace, where the alloy is melted, and the lead is removed 
in the form of litharge, or oxide of lead, by means of bel¬ 
lows; the silver is deposited in the cupel, which forms the 
bottom of the furnace. It is now in the form of silver 
bullion and is ready for the various uses to which it is to be 
applied. 

The chemical and physical properties of silver are such 
as to make it very valuable for many purposes in the arts 
as well as for money and manufacturing purposes. 

The chief uses to which silver is applied are as a medium 
of exchange or as money; for galvanizing and plating other 
metals; in the art of photography, and medicinally; also in 
the manufacture of jewelry, ornaments, medals, badges, 
buttons, bells and for many other useful and ornamental 
articles. 

Large quantities of silver are produced annually from 
the silver mines of the United States, Mexico, many of the 
countries of South America, from Spain, Germany and 
some other countries. 

In the use of silver for manufacturing purposes it is 
usually alloyed with some other harder metal; this is done 


THE TEACHER’S AID. 


227 


because silver is a very soft metal, and when used in the 
pure state it readily wears away. Imitations of silver are 
often made with alloys of other metals, the chief of which 
is aluminium. 

Note: Remarks on the uses, value, mining, manufac¬ 
ture, etc., of silver. 

QUICKSILVER. 

Mercury, or quicksilver, is a metal of a silvery-white 
color and a striking metallic lustre. It is the only metal 
that retains a fluid form at ordinary temperature. When 
pure it runs in small spherical drops over a smooth surface, 
but when not pure the drops become elongated and often 
leave a gray stain on a surface of glass or porcelain. The 
pure metal, when shaken in the air, presents no change on 
the surface, while if impure it becomes covered with a gray 
film. 

Native quicksilver only occurs in small quantities, usu¬ 
ally in the openings of mercurial ores. Cinnabar is the 
most important ore from which quicksilver is obtained. 

Two ways are employed for obtaining the metal from 
cinnabar. In one way the ore may be burned in a furnace, 
in which case the sulphur is given off as sulphuric acid, and 
the quicksilver is collected in a condensing vessel; by 
another method the ore may be distilled with slacked lime 
or iron filings or some other substance that will combine 
with the sulphur. 

The pigment known as vermilion is sulphide of mercury 
and is sometimes obtained from pure cinnabar, but is 
oftener a manufactured product. 

The uses of quicksilver are numerous and important. 
It is employed in the separation of gold and silver from 



228 


THE TEACHER'S AID. 


their ores by the process of amalgamation; its amalgams 
are largely used in the process of silvering and gilding, and 
some are used by dentists as fillings for teeth. 

It is indispensable in the construction of philosophical 
instruments, and in the laboratory it is used in the form of 
mercurial bath. Mercury is used in the construction of 
the mercurial thermometer, the barometer and for looking- 
glasses. 

Calomel is a production of mercury and is used for 
medicinal purposes. Corrosive sublimate is another, and 
although a very powerful poison is extensively used, in 
small doses, in chronic diseases of the nervous system and 
in skin diseases. 

It has been found that if cordage, canvas and wood are 
soaked in a solution of this metal they resist decay much 
better when exposed to the injurious influence of moisture 
and air. 

Note: Remarks on cost, uses, etc., of quicksilver. 

BRISTLES. 

Bristles are the strong hairs grown on the backs of hogs. 
They are extensively used in the manufacture of brushes, 
and also by saddlers and shoemakers. 

The quality of the bristles depends on their stiffness, 
length, color and straightness. White bristles being more 
valuable than the black ones. 

Hogs that inhabit cold countries produce the best quality 
of bristles. The Russian hog, from which large quantities 
of bristles are obtained, is a long, thin animal, and the 
longer and thinner the animal, the longer and stiffer the 
bristles. When this hog is sent farther south and fattened 
the bristles become quite soft and of less value. 


THE TEACHER’S AID. 


229 


The manner of collecting the bristles is as follows: During 
the summer the hogs are driven into the forest in large 
herds to feed on the roots, nuts, etc. They shed their 
bristles by rubbing against the trees. The bristles are then 
collected, packed and sewed up in ox or horse hides and 
sent to the market. From these local markets they find 
their way through the hands of agents to all parts of the 
world. 

A great quantity of bristles is used annually, and they 
form quite an important article of export from some coun¬ 
tries. 

Bristles vary in value according to the quality, from one 
hundred dollars to three hundred dollars per hundred 
weight. 

The countries from which bristles are obtained are 
Russia, Germany, Belgium, France and small quantities 
from China. 

Remarks on cost, uses, etc., of bristles. 


COKE. 

Coke is a production of coal; it is obtained by heating 
the coal in ovens or other places where very little air is 
admitted. In the process of obtaining the coke the coal is 
piled in round stacks or long ridges. 

During the building of the coal, large wooden stakes are 
driven in and afterward removed, and lighted coal inserted. 
As the coal ignites and becomes heated, large quantities of 
smoke and vapor are produced, which consist mainly of tar, 
water and coal-gas. 

As soon as the smoke ceases the process of “ coking ” is 
considered finished, and the mound or ridge of red-hot cin- 


230 


THE TEACHER'S AID. 


clers or coke is covered with fine coal-dust, which excludes 
the air and extinguishes the fire. 

In some places brick chimneys are built, and the coal 
built around these. The most economical plan is that in 
which the coking is done in fire-brick ovens. By this 
method the coal is admitted at the top, fire is applied and a 
little air is admitted through openings in front. 

When the coal ceases to send forth smoky vapor, every 
opening is closed, and the oven is allowed to cool for from 
twelve to twenty-four hours. The door in the front of the 
oven is then thrown open, and the coke is raked out while 
still hot. 

It is then sprinkled with cold water to stop the process 
of burning, and in this form it is ready for the market in the 
form of the coke of commerce. 

Coke is a hard, brittle, porous substance, varying in 
color from an iron-gray to a blackish-gray. It possesses 
more or less of a metallic lustre, has a metallic sound and 
does not soil the hands in handling. 

It produces a great amount of heat and is of great value 
as a fuel. It is used in stores, in furnaces, engines and in 
the smelting of metallic ores. It produces no smoke in 
burning. 

It is very light in weight, one ton measuring from two to 
three times as much as the raw coal. 

Coke, like coal, varies in price according to quality and 
the demand for it, and also upon the cost of production, 
shipping, etc. 

Remarks on the cost, uses, manufacture, etc., of coke. 


THE TEACHER'S AID. 


231 


GYPSUM. 

Gypsum is a mineral composed of sulphate of lime and 
water, the water forming about twenty-one per cent. It is 
found in many parts of the world and occurs in masses in 
clay and in the earth directly above deposits of rock-salt, 
and also above chalk deposits. 

It is found in crystal masses and in color varies from 
white to yellowish-white, gray, yellow-red, brown or black. 
The color depends on the chemical composition, the quality, 
amount and nature of the impurities. 

There are compact and earthy varieties, the masses of 
which are easily split or divided into plates and are easily 
cut, broken or scratched. The watery portion of gypsum 
is readily driven off by the action of heat. 

Burnt gypsum is easily reduced to a powder, in which 
state it is known as plaster of paris. It is very difficult to 
reduce unburned gypsum to a powder because of its tough¬ 
ness. 

When gypsum is white, fine-grained and translucent it 
is known as alabaster. Another variety, known as satin 
spar, is a fine, smooth, fibrous substance, displaying a beau¬ 
tiful play of light; it is easily scratched or marked and is 
used for ornamental purposes, such as inlaid-work, neck¬ 
laces, etc. 

Gypsum is soluble to a very small extent either in cold 
or hot water, or in acids. It is used as a fertilizer in North 
America and in Europe, in which case it is reduced to a 
powder by the use of mills constructed for this purpose. 

Remarks on cost, uses, etc. 


^ S 


232 


THE TEACHER’S AID . 


PLASTER OF PARIS. 

Plaster of paris is a powder derived from burned gyp¬ 
sum. It is a fine, white, heavy powder, and when mixed 
to a paste with water almost immediately sets and becomes 
a hard, solid substance. 

It is much used in the manufacture of artificial stone 
and in making castings, casts, cornices, etc. 

It is also used as a fine finishing for the interior of build¬ 
ings, and for both casts and models by sculptors. Plaster 
of paris makes an excellent and durable cement, and for 
this purpose it is largely employed. 

Gypsum is found abundantly in many parts of the world. 

Remarks on cost, uses, etc., of plaster of paris. 

S <£ & 

WHITE-WASH. 

White-wash is a preparation made from slaked quick¬ 
lime and water, reduced to the consistency of milk. It is 
a white fluid substance, and when kept stirred retains this 
appearance; but if allowed to stand the lime settles to the 
bottom, and the water has a clear, wheyey look. 

It can be colored any shade or tint desired, and is used 
to cover walls, ceilings, fences, etc., and for this purpose a 
little size is added to make it adhere. 

It is also applied as a coating to young fruit trees and 
ornamental shrubs and trees as a protection against animals 
and insects. 

White-wash is a good disinfectant, and is used for a great 
many sanitary purposes. 

Note: Remarks on the preparation, application, uses 
and cost of white-wash. 


THE TEACHER'S AID. 


233 


VERMILION. 

Vermilion is a pigment or paint of a peculiar bright red 
color. There are two varieties of vermilion, the native 
and the artificial. 

The native vermilion is a sulphuret of mercury, and 
occurs in bright red crystals or in dense masses of various 
shades of red and brown, and in this state is known as 
cinnabar. 

Artificial cinnabar is obtained by forming a mixture of 
sixteen parts of sulphur and one hundred parts of mercury 
and sublimating them in a retort. 

This produces a heavy, dull, red substance, very much 
resembling the native cinnabar, and which, when finely 
powdered, becomes a beautiful bright red. It was from 
this color the pigment received its name. 

Another method of obtaining artificial cinnabar is by 
the use of heat and water combined. The ingredients are 
ground to a fine powder in water at a temperature of 120 
degrees. The mixture, which is at first black, turns to a 
brownish or reddish color, when the temperature is lowered 
about fifteen degrees and kept thus until the residue has 
become a bright red. 

The water is then drawn off and the vermilion washed 
clean. The artificial vermilion is the chief vermilion of 
commerce and is largely employed in the arts. Chinese 
vermilion has always been noted for its beauty and quality. 

Vermilion is used in the mixture of paints requiring red 
or shades of red. It is a very durable paint when not adul¬ 
terated with cheap ingredients. It varies in price accord¬ 
ing to quality. Large amounts of vermilion are used annu¬ 
ally in the painting of buildings, etc. 

Note: Remarks on the uses, cost, preparation, etc., of 
vermilion. 


234 


THE TEACHER'S AID. 


ALABASTER. 

Alabaster is a compact variety of sulphate of lime or 
gypsum; it has a fine, smooth texture and is usually white, 
but sometimes yellowish, red or gray. 

Alabaster proper is a white, granular, semi-transparent 
variety of gypsum or sulphate of lime. It is made into a 
variety of small objects of sculpture, vases, stands, orna¬ 
ments, etc. 

Real alabaster can easily be scratched with the nail. 
The name is often applied incorrectly to a compact variety 
of carbonate of lime. This carbonate is known as gypsum- 
alabaster; and being soluble in water, it cannot stand 
exposure to the weather, as its softness makes the surface 
readily become rough and opaque. Like the true alabas¬ 
ter, it is made into ornaments, etc. 

The name alabaster is derived from a town in Upper 
Egypt, where this kind of stone was abundant and was 
manufactured into vases for perfumery. The usual appli¬ 
cation of the word implies whiteness and smoothness. 

Remarks on uses, cost, etc., of alabaster. 

*,$8 

CELLULOID, 

Celluloid is a substance obtained from the cellular tissue 
of plants. It is a smooth, hard, compact substance, 
closely resembling ivory, and is obtained by subjecting 
cellulose tissue to the action of strong nitric acid. 

Cellular tissue in plants is the organic matter which cor¬ 
responds with the flesh in animals. It exists in all plants 
to a greater or less degree. In some plants, such as mosses, 
it forms the entire surface. 

Cotton, linen, paper and all like substances which origi- 


THE TEACHER'S AID. 


235 


nate from vegetable fibre, when immersed in a solution of 
nitric acid, results in a mixture of two nitro-celluloses. 

This product, when dissolved under pressure at a high 
temperature, produces the substance known as celluloid. 

Celluloid becomes pliable at a temperature of 125 de¬ 
grees. Coloring matter may be introduced into the cellu¬ 
loid during the process of manufacture, and any shade or 
color produced. 

It is used to make ornamental picture frames, combs, 
backs for brushes, handles for knives and umbrellas, backs 
for books and many other useful and ornamental articles. 
It is very inflammable and should be kept away from the 
fire. 

Remarks on cost, uses, etc., of celluloid. 

PLASTER. 

Plaster is a composition of lime, sand, water and hair. 
It is used in covering walls, partitions and ceilings. Plaster 
is usually applied in three coats. The first coat is the solid 
foundation on which the others are placed. 

The first coat is allowed to dry thoroughly, then the 
second coat is applied over the first and rubbed and 
smoothed so as to make an even surface, and before the 
second coat has completely dried the third or finishing coat 
is applied. 

This coat is made of finer material and is applied in a 
more liquid state and can be tinted any desired shade. In 
cases of ceiling, cornices, mouldings, etc., plaster of paris is 
generally used. This sets or hardens more rapidly than 
lime and has a finer and whiter surface. 

When plaster is being applied, and until thoroughly 
dried, care has to be used that the proper temperature is 


236 


THE TEACHER'S AID. 


attained, as an extreme of heat or cold is liable to crack it 
and thus spoil its value and appearance. Plaster is a gray- 
colored substance—hard, coarse, flinty and insoluble in 
water when set, but partially soluble when soft. 

Uses and cost of plaster, etc. 

j* 

VENEER. 

Veneer is a thin layer of wood, glued to the surface of a 
more common, or coarser kind, to give it a better finish and 
appearance. Only very choice kinds of hard wood are used 
for veneer. These are sawed very thin, in many instances 
as thin as paper, and, being glued onto soft pine or other 
soft wood, give it the appearance of solid hardwood. And 
in this way a piece of cheap furniture has the appearance of 
a very rich article. 

When the veneers are polished and varnished, all the 
grains in the wood are brought out distinctly, and the effect 
is very pleasing. Veneer takes its color from the wood from 
which it is obtained; thus, if the wood be either light or 
dark, the veneers produced are correspondingly light or 
dark. The principal hard-woods used for veneers are 
mahogany, oak, walnut, and rose wood. Especially the 
knots and curly roots of these trees. 

Remarks: Uses, where found, cost, transportation, 
scarcity, manufacture, other kinds of wood used, etc. 

& & .jt 

ASHES. 

Ashes are what remains of animal and vegetable sub¬ 
stances after they have been consumed by fire. The ashes 
of vegetable substances contain salts of potash, silica, lime, 
soda and iodine. 



THE TEACHER'S AID. 


237 


The ashes of peat or turf contain alkalies, combined with 
more or less sand and clay. 

The animal ashes differ very little from vegetable ashes. 
They consist chiefly of phosphoric acid combined with lime. 
In color ashes vary from a light gray to darker shades, the 
animal ash being usually the darker colored. 

Wood ashes are generally of a gray color, but vary 
according to the substance from which they are obtained. 
They are a light, fine, powdery substance, and when mixed 
with water form a muddy looking paste. 

Wood ashes form a valuable article of commerce in some 
localities, being used in the manufacture of soaps, in 
dyeing, and in the manufacture and preparation of glass. 

They are used extensively as a fertilizer, and for domestic 
purposes, for scouring and cleaning wooden and tin articles. 

Animal ashes vary in color from gray to black; they are 
a heavy, oily substance, very often having a disagreeable 
smell, while the wood ash is devoid of all smell. 

Amimal ash is used in black paint, and is known as 
“bone black;” it is also used in black varnishes, etc., and 
as a fertilizer. When in the form of “ bone black ” it has a 
greasy, sticky appearance. 

Note: Remarks on cost, uses, etc. 

jt 

WHETSTONE. 

Whetstone, or hone, is a peculiar kind of stone used for 
sharpening edged tools, such as knives, scythes, razors, 
shears, etc. These stones are a variety of shale, or slate, and 
differ greatly in quality. 

The oil stone, considered the best quality, is used for 
sharpening fine instruments, such as razors and fine 
surgical instruments. The coarser stones are used for 


238 


THE TEACHER'S AID. 


sharpening the coarser tools, such as axes, machinery, etc. 

These stones are usually cut into pieces about one foot 
long, and from one and one-half to two inches thick, and are 
made either square-cornered or round, according to the use 
for which they are made. 

In color these stones are gray, blue-gray, or yellowish- 
gray, and green. The light-green variety, from Levant, is 
the most valuable, and is called “ hone-stone. ” It should 
be kept in a damp place, that it may not become too dry 
and hard 

They are quite hard, and when they are being used either 
oil or water must be applied to them, in order to get the best 
results in the sharpening of tools. The application of oil, or 
water, prevents the stone from wearing away too rapidly, 
as it 'VYOuld otherwise do, if nothing was applied to keep the 
stone moist and cool. 

Cost, where obtained, etc. 

& & 

SAND PAPER. 

Sand paper is made by sprinkling sand over paper 
which has previously been covered with a coating of glue on 
one side. In order that the sand may properly adhere, it is 
applied while the glue is still soft. 

Sand paper is used for polishing and smoothing surfaces. 
It is employed to remove the old paint from woodwork, and 
make the wood smooth and even and suitable for receiving 
another coating of paint. 

Sand paper also furnishes a suitable and convenient sur¬ 
face for producing friction with matches. 

It is used by cabinet-makers, by carpenters and 
painters in their various lines of work. The paper 


THE TEACHER’S AID. 


239 


employed in the manufacture of sand paper is usually a 
coarse, heavy paper, which may be of any color. That 
intended for polishing purposes is quite tough and durable. 

It is of a grayish or sand color, and is quite inexpensive. 

Note: Remarks on uses, cost, etc., of sand paper. 

& jt, 

GRIND-STONE. 

Grind-stone is a flat, circular stone, made of different 
varieties of sand-stone, and used for grinding or sharpening 
tools. 

Theses stones are of various degrees of coarseness 
owing to the kind of sand-stone used. They are of various 
sizes, ranging in weight from a few pounds to hundreds 
of pounds. 

In size and weight they are adapted to the work they are 
intended to perform. They are used in the manufacture of 
cutlery, saws, machinery, etc. 

The finer grades of stone being used on instruments 
which require a very fine finish, and the coarser stones for 
coarser instruments, or ones that do not require a sharp 
edge. 

These stones are made to revolve upon an axis, and the 
instrument to be sharpened is held on the stone as it 
revolves. Water, or oil, is usually applied to the surface of 
the stone during the operation. 

This facilitates the process, and prevents the cuttings of 
the stone, and those of the article being ground, from 
floating through the air and being inhaled by the workmen. 

Grind-stones are of a gray, whitish-gray or yellowish-gray 
color, and more or less porous. Grind-stones are almost 
indispensable where edged tools are employed. 

The value of grind-stones varies according to the quality 



240 


THE TEACHER'S AID. 


and size, the very large ones being extremely expensive, 
while some of the very small ones are quite cheap. 

Note: Remarks on uses, cost, etc. 

GUM. 

Gum is a vegetable mucilage, or juice, which exudes 
through the bark of certain varieties of trees. It collects 
in lumps on the bark and becomes dry and hard by exposure 
to the air and heat. It is soluble in water, to which it 
imparts an adhesive property. 

The natural gums vary in color from white to yellowish, 
red and brown. The lighter the color, the better the gum. 
When dry it is transparent, or nearly so, and is somewhat 
brittle, but is not easily pulverized. 

Gum is produced by trees that are natives of warm coun¬ 
tries, as the accacia, palm, etc. Although some trees that 
are natives of cold climates produce large quantities of 
gum. To this latter class belong the peach, cherry and 
plum tree. 

The natural gums are collected from the trees when dry, 
or nearly so. They are dissolved in hot water, and are 
freed by straining or filtering from all impurities, such as 
bark, etc. This fluid gum is then put into moulds or 
vessels and allowed to cool. The water evaporates, and 
the pure gum which remains becomes hard and dry. 

The different varieties of gum are used for different 
purposes; some being used by confectioners in the manu¬ 
facture of candies; some in the manufacture of a stiffening: 
material for silk, cotton and linen cloths, and in medicine 
and perfumery. 

Substitutes are manufactured to take the place of the 
natural gums. They are made from potato-starch, wheat- 


THE TEACHER'S AID. 


241 


starch and sago-starch, and are much less expensive and 
more easily dissolved and applied. 

These substitutes are used in the preparation of calico, 
muslin and other fabrics, and for gumming stamps, paper, 
books, etc. The gum substitutes are manufactured on a 
very extensive scale, and form a very important and neces¬ 
sary article of commerce. 

Remarks on cost, uses, etc., of gum and gum substitutes. 

jt 

PITCH. 

Common pitch is the residue remaining after the distilla¬ 
tion of wood tar. It is a thick, black, highly odorous 
substance. 

It is produced extensively in North America, Norway 
and Russia, being in reality a product of the manufacture of 
tar; it is obtained wherever tar is manufactured. 

It is obtained not alone from wood tar, but from bone 
and coal tar as well. But the pitch obtained from wood 
tar is superior to coal pitch, being much tougher and, 
therefore, more serviceable. 

It is a useful substance for protecting wood, cloth, rope, 
etc., from the destructive action of water, and is, therefore, 
used for coating the outsides of ships and boats, for calking 
seams, and for coating ropes and sails; also for the inside of 
water casks and tanks, and other similar purposes. 

It is used in the manufacture of asphalt for building and 
paving purposes, and for the black varnish used for coating 
ironwork in order to prevent it from rusting. 

Pitch is solid at ordinary temperature, but softens and 
melts when subject to a small amount of heat, and has a 
disagreeable smell. 

Remarks on cost, uses, manufacture, etc., of pitch. 

16 




242 


THE TEACHER’S AID. 


WHALEBONE. 

Whalebone is procured from the baleen plates in the 
mouth of the baleen whale, and, when prepared, constitute 
the whalebone of commerce. They vary in length from a 
few inches up to ten feet, and in extreme cases to twelve 
feet. 

Their chemical composition is albumen, hardened by 
small portions of lime. Their natural color is a bluish-black, 
but in some species they are striped lengthwise with a 
whitish or yellowish color. These plates terminate at the 
point in a number of coarse, black fibres, which are found, 
more or less, down both sides of the plates or blades. 
These coarse fibres are much used by brush makers. 

To prepare whalebone for the market, the fibres are 
removed from the end and sides of the blades, and the flat 
sides of the blades are generally scraped. The blades are 
then boiled in water for several hours, until they become 
soft enough to cut with a knife. They are then cut into 
lengths suitable for the purpose to which they are to be 
applied. 

With the process of boiling, dying is generally combined. 
The object of dying being to make the whalebone perfectly 
black, as this is considered more pleasing in appearance than 
the natural color. 

Whalebone is generally used in strips, such as stays, 
umbrella ribs, etc., and is very easily split for this purpose. 
Strips of rattan cane are dyed black and used as a cheap 
substitute for whalebone. 

Remarks on uses, cost, color, substitutes, etc., of whale¬ 
bone; also upon the whale, where found, size, etc. 


THE TEACHER’S AID. 


243 


MAHOGANY. 

Mahogany is the wood of a tree that is a native of the 
West Indies and South America. It attains a height of 
from eighty to one hundred feet, and in dimensions is 
second to few other trees. Its timber is generally sound 
throughout, even in the largest trees. 

The occupation of cutting this timber and removing it to 
the coast for shipment is exceedingly laborious work, and 
employs a large number of men and oxen. 

The wood varies much in value, according to the color, 
and beauty of the curl. Single logs have realized as much 
as one thousand pounds for cutting into veneers, in which 
state it is generally used, as its great weight and value 
prevent it from being used solid. 

Mahogany holds the highest position as a cabinet wood. 
It is used in the manufacture of the very finest furniture, 
musical instruments, picture frames, ornamental boxes, etc. 
It is susceptible of a very high polish, which fits it for the 
above uses. 

Note: Remarks on cost, uses, etc., of mahogany. 

jt 

NITRE. 

Nitre, or saltpetre, as it is frequently called, is the 
nitrate of potash. It usually occurs in long, colorless, 
striated, six-sided prisms; its taste is cooling and very 
saline. 

Nitre occurs as a natural product in the East Indies, 
Egypt, and Persia, where it is found sometimes as an 
effervescent upon the soil, and sometimes disseminates 
through its upper strata. 

The crude nitre is obtained by lixivating the soil and 



244 


THE TEACHER'S AID. 


allowing the solution to crystallize. Nitre does not exist in 
any living member of the animal kingdom, but is found in 
the juices of various plants, amongst which may be named 
the sunflower, nettle, goose-foot, tobacco, barley, ecc. 

Nitre is used in the manufacture of sulphuric acid, in the 
preparation of nitric acid, and as an oxidizing agent in 
numerous chemical operations; as an ingredient for fire¬ 
works, and especially in the manufacture of gunpowder. 

It is also extensively used in medicine, in the arts, and as 
a preservative for meats. It is a white, crystalline salt, 
with an acrid, bitter taste. It is not a very expensive 
article. 

Note: Remarks on cost, uses, etc., of saltpetre. 

& 

STONE. 

Stone is a mass of concrete, earthy or mineral matter. 
In popular language, very large masses are called rocks, 
smaller masses are called stones, and the finer kinds, gravel 
or sand, or grains of sand. 

Stone is used for a great variety of purposes. It is used 
in the construction of buildings of all kinds, for walls, 
fences, piers, abutments, arches, monuments, sculpture, 
paving, millstones, grindstones, hearthstones, etc. 

The most desirable properties in a building stone are 
that it should be compact, insoluble in water, not easily 
altered by the action of the elements and not likely to take 
on a coating or growth of vegetable matter. These qual¬ 
ities depend on its chemical composition and structure. 

Building stones are divided into three classes, the silici- 
ous, calcareous and composite. Silicious stones, which 
include granite, porphyry, gneiss, greenstone, basalt, sand¬ 
stone, slate, serpentine, etc., and contain from 45 to 99 


THE TEACHER'S AID. 


245 


per cent of silica, are, as a general rule, the most durable 
for building. Their durability is affected by some of the 
ingredients in their composition, as the feldspar in granite 
and the salt of iron in sandstone. 

Calcareous stones, such as simple limestone, marble, 
etc., are slightly soluble in water, and they are liable to 
splinter by water freezing in their pores; they are acted 
upon by acid gases, and are somewhat liable to be stained 
by vegetable growths. Yet some of them are durable 
enough in a country atmosphere. 

The difference in the action of the atmosphere in large 
cities and in country districts may be seen in the fact that 
the magnesian limestone selected for the construction of 
the British House of Parliament proved a failure by being 
unable to withstand the destructive action of the elements 
of a large city, and yet the same stone would last for cen¬ 
turies in a country church. 

Artificial stones would include, properly speaking, the 
burned clay wares used for building purposes, such as 
brick, terra cotta, tiles, etc., as well as the various cements. 

The manufacture of artificial stone has attracted much 
attention during the last thirty years, and it has developed 
into a very profitable industry. 

This artificial or manufactured stone is produced by the 
silicious cementing properties of soluble alkaline, silicates 
and sand. The process, which was first used about the 
year 1825, consisted in mixing the gelatinous silicates of 
soda with sand and a little powdered clay and glass in the 
proportion of one part glass, ten parts sand, one part clay 
and one part silicate of soda. These proportions are some¬ 
times varied. 

These ingredients are mixed in a pug-mill, to the con¬ 
sistency of putty, and in this plastic state this compound 



246 


THE TEACHER'S AID. 


is very easily moulded into an endless variety of forms of 
plain and elaborate designs. 

After being moulded, the objects are dried in close 
ovens first and then removed to kilns where they are fired 
at a gradually increasing temperature, which finally reaches 
a red heat. The objects, when placed in the kiln, are 
covered over with dry sand to prevent them from becoming 
misshapen, which so commonly disfigures large objects 
made of baked clay. 

When the process of firing is completed the objects are 
then in the form of a semi-vitrified mass, which has the 
appearance, properties and composition of fine sandstone. 

A hard and durable compound is made without baking, 
by a double composition of silicate of soda and chloride of 
calcium. In this composition sand, chalk and other min¬ 
erals are mixed with a proper quantity of a solution of silica 
of soda, this being performed by means of a pug-mill. 

The mixture is now in a plastic state and can be moulded 
into any desired shape, after which the objects are sub¬ 
jected to a solution of chloride of calcium. The silica 
readily combines with the calcium and immediately forms 
an insoluble silicate of lime, which cements into a solid 
mass all the particles of sand, lime, etc., which are used in 
the composition. 

The objects into which artificial stone can be manufac¬ 
tured are numerous; in fact, whatever is made of real stone 
can also be made of the artificial. Among the most com¬ 
mon uses to which it is applied are the manufacture of 
grindstones, millstones, tombstones, monuments; chim¬ 
neys and chimney-pieces, balustrades, fountains; statuary 
and many other useful and ornamental articles too numer¬ 
ous to mention. 

In 1872 a process was invented for the manufacture of 
a very compact stone, which was made by the combination 


THE TEACHER'S AID . 


247 


of lime and a natural soluble silica with sand and silicate of 
soda. This composition was found to excel Portland stone 
and would not break as readily from a crosswise strain. 

Some varieties of stone are very expensive, and others 
are inexpensive. The finely polished and dressed stones 
are more costly than the ones in their rough, undressed 
state; and the stones that are imported from other coun¬ 
tries are always more expensive than the native stones. 

Note: Remarks on cost, uses, formation, etc., of stone. 

j* j* 

COCOA. 

Cocoa, or, more properly speaking, cacao, is a valuable 
dietary substance obtained from the seeds of a species of tree 
that belongs to the tropical parts of the American conti¬ 
nent. 

The common cacao tree is of low stature, seldom exceed¬ 
ing sixteen to eighteen feet in height; it is taller in its native 
state than when cultivated in plantations. 

The leaves of this tree are large, smooth and glossy, and 
grow chiefly at the end of the branches, but in some cases 
they spring directly from the main trunk of the tree. The 
flowers are small and occur in numerous bunches on the 
main branches and the trunk; this arrangement of the 
flowers is peculiarly remarkable, and it gives to the mature 
fruit the appearance of being artificially attached to the 
tree. 

A cluster of blossoms usually produces only one matured 
fruit. When ripe the fruit is in the shape of a pod, which 
is from six to ten inches in length and from three to four 
and one-half inches in diameter. The interior of the fruit 
or pod is arranged in five cells, in each of which is a row of 
from five to ten seeds imbedded in a soft, delicately pink, 



248 


THE TEACHER'S AID. 


acid pulp; each fruit will thus contain from twenty to forty 
or more seeds, which constitute the raw cocoa or cocoa 
beans of commerce. 

The cacao tree seems to have been originally a native of 
Mexico, but it can be cultivated in suitable situations within 
the twenty-fifth parallels of latitude. It flourishes best 
within the fifteenth parallel, at an elevation ranging from 
near the sea level to as high as two thousand feet. 

This tree is now cultivated in Mexico, Honduras, Gua¬ 
temala, Brazil, Nicaragua, Peru, Ecuador, New Grenada, 
Venezuela, Guiana and most of the West Indian islands. 

The cacao tree was cultivated and its products held in 
the highest esteem in Mexico and Peru previous to the dis¬ 
covery of America by Columbus. A knowledge of the val¬ 
uable food was first brought to Europe by Columbus, but 
some time elapsed before its virtues were appreciated in the 
old world. 

About the beginning of the eighteenth century cocoa in 
the form of chocolate had become an exceedingly fashion¬ 
able beverage, and the cocoa tea was a favorite sight at 
places of public refreshment. But the high price at which 
it was retailed placed it among the luxuries, and it was 
therefore used almost exclusively by the wealthy. As an 
article of food cocoa is exceedingly nutritious. 

In the manufacture of cocoa the first operation consists 
in roasting the seeds. This is accomplished by the use of 
large cylinders in which the seeds are placed and heat 
applied. When this process is completed the seeds are 
taken to the crushing and winnowing machine, where they 
are reduced to the form of nibs; the nibs are next separated 
from the shells by the use of a powerful fan blast. 

The next process is winnowing, during which operation 
the nibs are placed in small quantities in hand sieves, where 
the hard cocoa kernels are sifted out, and all mouldy or 


THE TEACHER'S AID. 


249 


discolored fragments are at the same time removed by 
hand. 

The nibs prepared in this way constitute the simplest 
and purest form in which manufactured cocoa is sold. The 
nibs, when ground fine, can be cooked much easier. 

Another form in which the pure seeds are prepared is in 
flake cocoa, which consists of nibs ground into a coarse, 
uniform paste. The grinding is effected in a cylindrical 
machine having an outer fixed covering within which a 
drum rotates. The nibs are fed into this machine by means 
of a hopper at the top, and are carried around its circum¬ 
ference by the rotation of the drum and pass off as a thin, 
pasty mass. 

Most other preparations, whether sold as cocoa or choco¬ 
late, are mixtures made of various other substances with 
the ground nibs, the object of these mixtures being to con¬ 
ceal the presence of the cocoa fat and render the mixture 
soluble in boiling water. 

The ordinary difference between the soluble cocoas and 
chocolate is that the cocoa is usually sold in the form of 
powder, and the chocolate is put up in the form of cakes 
that require to be scraped and boiled to be made ready for a 
beverage. 

The nibs for the manufacture of chocolate are reduced to 
a fine, pasty state in heated mills, and the sugar, or the 
sugar and starch with vanilla, are added, and thoroughly 
incorporated in the mill. 

The paste is next passed several times through heavy, 
horizontal rollers, in order to produce a complete mixture. 
It is next cast into moulds while in a pasty condition, and 
after cooling it forms hard, solid cakes, in which form it is 
ready to be wrapped and labeled, and is then fit for the 
market. 

Some of the varieties and brands are quite expensive, 



250 


THE TEACHER'S AID. 


while others are cheap. The prepared cocoa and chocolate 
will keep for an indefinite time, and are always ready 
for use. 

Cocoa is used in the manufacture of chocolate candies, 
for which large quantities are annually consumed; choco¬ 
late is used in making icings for cakes, in puddings, cus¬ 
tards, ices, etc. 

Remarks on cost, uses, manufacture, etc., of cocoa. 

jt, jt jt 

COPPERAS. 

Copperas is a sulphate or salt of iron, of various colors, 
as green, gray, yellowish or whitish, but more frequently 
green; it has a peculiar, astringent taste. It readily dis¬ 
solves in water, but is insoluble in alcohol. 

Copperas is frequently found in metalliferous mines. It 
is obtained by precipitating a solution of protosalt of iron 
with sulphate of soda, which results in throwing down a 
precipitate of phosphate, or copperas. It is also known as 
green vitriol. 

The copperas of commerce is usually made of a decompo¬ 
sition of iron and pyrites. The term copperas was synony¬ 
mous with vitriol, and included the green, blue, white, or 
the sulphates of iron, copper and zinc. 

It is extensively used for dyeing purposes, especially for 
the production of a good black; in the manufacture of many 
varieties of ink; in the tanning of leather; in the manufac¬ 
ture of Prussian blue and sulphuric acid; it is used medicin¬ 
ally as an astringent and as a tonic; it is also used exten¬ 
sively in analytic chemistry. 

It is a hard, flinty substance, resembling pieces of colored 
glass or stone. It can easily be reduced to a powder, but is 
usually obtained in small lumps of various sizes. It is 


THE TEACHER’S AID. 


251 


quite inexpensive. There are a great many domestic 
purposes to which copperas is applied and for which it is 
very highly prized. 

Remarks on cost, uses, manufacture, etc., of copperas. 

j* jt 

COPPER. 

Copper is a metal of a pale red color, with a tinge of 
yellow. It is one of the oldest known metals, and derives 
its name, presumably, from the island of Cyprus, where it 
was first obtained and used by the Greeks. 

In very early times this metal was apparently not used 
alone, but always in combination with other metals, 
usually tin, forming an alloy which at the present time is 
known as bronze. 

It is reasonable to suppose that the large quantities of 
copper which the Phoenicians obtained from their mines in 
Cornwall was as much a reason for their researches for 
metal in Great Britain as was the quantities of tin which 
they obtained. 

Next to gold, silver and platinum, copper is the most 
ductile and malleable of metals, and it is more elastic than 
any metal except steel, and the most sonorous of all 
metals. 

Copper is sometimes found native in a state of purity, 
but as a general thing it is combined with oxygen, water 
and carbonic acid. It is usually found native in laminea, or 
fibres, almost always quartuous. It occurs in small quanti¬ 
ties as oxide and sulphate; and in such cases the ore is 
obtained from fissures or veins in the rocks. It is also 
found crystallized, and in grains of superficial laminea, on 
stone and iron. 

Copper is not in any way affected by contact with water, 



252 


THE TEACHER'S AID. 


but it tarnishes readily by exposure to the air, and finally 
becomes covered with a green coating of carbonate of 
oxide; it is also acted upon by some of the stronger acids, as 
sulphuric acid, and some others. 

The extraction of copper from the various ores combined 
with it is a very complicated, tedious and difficult process. 
The chief difficulty is met with in the separation of the iron 
and sulphur from the copper. 

The ordinary method of reducing the ores consists in 
burning away the sulphur in the form of sulphurous acid, 
and removing the iron in the form of slag, by means of 
fluxes. There are many different and distinct steps in this 
process, before commercially pure copper can be obtained. 

Copper is the only red metal; it can be cast, rolled, 
hammered, drawn or fused. Its malleability permits it to 
be hammered into very thin plates or sheets; owing to its 
ductility, it can be drawn into very fine wire; and its 
tenacity is only a little less than that of iron. 

It is a powerful conductor of electricity, and for this 
reason it is used in the construction of lightning conductors 
and telegraph wires for underground and sub-marine lines 
of communication. Copper is used for coining certain 
denominations of money in some countries. 

Copper, when formed into sheets, is used as a covering 
for the bottoms of ships, for boilers, and other utensils; 
when combined with zinc and tin, it is used for enamel¬ 
plating, for dyeing, etc. When mixed with tin, it forms 
bell-metal; when mixed with a small proportion of bronze 
in combination with zinc, it forms brass, pinchbeck, etc. 

When copper is introduced into the human or animal 
bodies, it acts as a violent emetic. All the preparations of 
copper are strong irritant poisons. If acidy fruits or 
vegetables are cooked in copper vessels, the eating of such 


THE TEACHER'S AID. 


253 


fruit is often attended with poisonous, and sometimes 
deadly results. 

Many compounds are made of copper. There are two 
oxides of copper, known as the black and the red; the latter 
of which is used in the manufacture of glass, as a coloring 
matter, when a ruby-red tint is required. 

A carbonate of copper, known as green rust, forms on the 
surface of the copper sheathing on ships, on copper coins, 
and on vessels made of copper, which are allowed to remain 
in a damp place. This carbonate is very poisonous, and 
hence the barnacles which attach themselves to the copper 
sheathing are poisoned; and food eaten from vessels 
where this green rust has formed produces poisonous 
results. 

The carbonate of copper under the name of blue verditer 
is prepared in large quantities and sold as a pigment. 
Blue and green verdigris are obtained by the action of 
acetic acid upon the oxide of copper. 

Blue vitriol is produced by dissolving the black oxide in 
sulphuric acid and allowing the salt to crystallize out. The 
crystals formed are large, and of a fine blue color, and being 
soluble in water they are extensively used in the dyeing of 
calico, and in the making of several fine blue and green 
colors; also in the manufacture of writing inks, and in a 
solution made for the prevention of dry rot in some kinds of 
wood. 

Copper ores are found mixed with silver, mercury, zinc, 
antimon} r , iron, arsenic and sulphur. These ores are found 
widely distributed over the earth’s surface. Great masses 
of native copper have been found in both North and Soutli 
America. South Africa also furnishes some very pro¬ 
ductive copper mines. Large amounts of copper are 
obtained from Australia, Cuba and Chili. The principal 
yield of copper ore in Great Britain is obtained from the 


254 


THE TEACHER’S AID. 


copper mines in Cornwall. In the vicinity of Lake Superior 
copper ore occurs abundantly, and remarkably thick veins 
of rich, metallic copper ore are found there, and also in 
many of the Northwestern states of the Union. 

Note: Remarks on the cost, uses, manufacture, etc., of 
copper. Tell about the copper mines and fields of the 
United States, amount of ore produced, etc. 

BULLETS. 

Bullets are projectiles made of lead or iron, and intended 
for use in guns, revolvers and cannons, and when used with 
the above named weapons their object is either defensive or 
offensive. 

In war, they are used for offensive and defensive pur¬ 
poses ; in time of peace, by the sportsman and hunter in the 
pursuit of game, in target practice, etc. 

From the date of the invention of gunpowder, at the 
beginning of the last century, balls of a spherical form 
were made. Balls for cannon are made of cast iron, and 
those for muskets are made of lead. 

Numerous experiments have been made in order to 
determine the most suitable form for bullets. 

Leaden bullets have been made with steel points 
affixed. When the smooth-bore muskets were exclusively 
used by army infantry, the bullets were made by casting; 
in this operation the moulten lead was poured into moulds 
of the desired form and size, the lead being heated only 
sufficiently to make it assume a fluid form, and the moulds 
were cooled after being used once or twice, by being dipped 
into cold water. 

Various machines have been invented by which bullets 
are made from bars or rods of ad. Some of these machines 


THE TEACHER'S AID. 


255 


cast the pieces that are cut from the bars, into moulds, 
where the bullets are formed; in other machines, the 
pieces are passed into dies where, by compression, they are 
given their form. 

For use in these machines, the lead is first cast into bars 
about a yard in length by five-eighths to three-fourths of an 
inch in thickness. This rod is passed between rollers, to 
increase its density, and again between other rollers that 
press it into a row of nearly globular pieces; each piece is 
then given its proper form by the use of a spherical die. 
Lastly, a punch, worked by a treadle, separates the pieces 
into bullets. 

By the use of one of these machines, and two dies, nine 
boys can produce forty thousand bullets in a single day’s 
work. 

One kind of machine cuts the pieces of a suitable size for 
the bullets, from the bars of lead which are regularly fed to 
it, and compresses them into the kind of bullet desired for 
use in muskets, pistols, rifles, etc. 

Every revolution of the machine produces eight of these 
bullets, and twenty-five revolutions per minute can be 
attained. 

Bullets for use in the Enfield rifles are made with great 
skill and rapidity. The machine for this work draws in a 
coil of leaden rod of the desired thickness, unwinds it, cuts 
it into the desired lengths, stamps out the bullets with 
steel dies, drops them into boxes and carries them away. 
Each machine, with its four dies attached, makes seven 
thousand bullets per hour, and four such machines will 
easily turn out three hundred thousand bullets as the 
outcome of a day’s work. 

These machines are so complete, and so nearly auto¬ 
matic, that one workman can attend to all of them. 


256 


THE TEACHER'S AID. 


Bullets vary in size and shape according to the use for 
which they are desired. The old style spherical bullets, 

which were made for use in carbines, muskets and pistols, 

\ 

are rapidly passing out of use and being succeeded by 
others of a more suitable form. 

These forms are numerous, and include the following: 
The egg-shaped bullet with the center of gravity at the 
larger end; ovoid, with a hemispherical cavity at one end; 
a spherical ball placed in a wooden cup, and having pro¬ 
jections on the outside; oval, having a plug made of mixed 
metal driven into a hole scarcely large enough for it; and 
various elongated shapes, having some kind of plug, which 
was driven into the lead by the force of the explosion, 
thereby filling the grooves in the rifle barreling. 

Large quantities of all kinds and sizes of bullets and balls 
are manufactured and used annually. Some varieties are 
quite expensive, while others are cheaper. The price 
depends to a certain extent on the size, the material used, 
and the uses for which they are intended. 

The manufacture of bullets and balls is carried on 
extensively in almost all civilized countries. 

Note: Remarks on the cost, uses, manufacture, etc., of 
bullets and balls. 


£ & 

INDIGO. 

Indigo is a blue dye obtained from the leaves and stalk 
of the indigo plant. It is a beautiful, durable and very 
valuable dye, and is the basis of all blue dyes, and also of the 
best black dye for woolen goods. 

Indigo has been used in India from very early times, and 
the cultivation of the indigo plant, which was at first con¬ 
fined to India, has spread to other tropical and sub- 


THE TEACHER'S AID. 


257 


tropical countries; and this plant is now profitably culti¬ 
vated in the West Indies, Mexico, Brazil and Egypt. 

It is a shrubby plant, from two to three feet in height. 
The leaves are pinnate and appear in pairs, five or six 
leaves appearing along the sides of the central stem; they 
are long and of a bluish green color. The flowers, which are 
pale red, appear in bunches. 

The indigo plant while growing exhibits no appearance 
of yielding such valuable dye-stuff; nor has it been defi¬ 
nitely ascertained in what form the indigo exists in the 
plant. 

In the cultivation of the indigo plant, the seeds are sown 
in drills about ten inches apart. The plant soon makes its 
appearance above the ground, and constant care is required 
to keep away the weeds, which, if allowed to grow, would 
soon smother the tender plant. 

When about three months old, the plants begin to 
bloom, and are then cut down and are ready for use. A 
second crop soon sprouts up from the old stalk, and very 
often a third crop is obtained in a year. 

Formerly the plant was dried after cutting, fire heat often 
being employed. It is now generally considered better to 
use the plant when freshly cut. 

The freshty cut plant is placed in a large wooden vat and 
pressed down by beams. 

Enough water is added to cover it, and allowed to stand 
from ten to twelve hours, when fermentation sets in. 
Large quantities of gas escape, and the water becomes a 
light green color. 

This green fluid is drained off into another vat, which is 
placed below the level of the first. Here it is stirred, and 
kept in motion, by means of poles, which causes the green 
coloring matter in the water to become suspended, or 
separated, and to appear as a blue, granular substance. 

17 


258 


THE TEACHER’S AID . 


When the particles of indigo appear to be collected, they 
are allowed to settle, and the sediment emptied into 
another vat, which is below the level of this one. 

From this it is pumped into boilers, which are slightly 
heated, and then permitted to stand for several hours, 
during which time the indigo settles to the bottom, and as 
much as possible of the clear water is drawn off from 
above it. 

Heat is again applied to the boiler and the contents 
brought to a boiling point. The contents of the boiler are 
then poured onto a frame made of wood covered with cloth, 
where they are permitted to drain until of the consistency of 
cream. 

Pressure is next applied until the substance becomes as 
dry as ordinary soap, when it is cut into blocks or cubes 
and placed on shelves in the drying houses, and so arranged 
as not to touch each other during the drying process. 

When thoroughly dry, the cakes are freed from dust, etc., 
and packed in boxes, and in this form are ready for the 
market, and constitute the indigo of commerce. 

Indigo is considered the oldest dye in use, and few 
materials are of more use to the dyer; but great care and 
skill are required in using it, in order to obtain successful 
results. 

Pure indigo has a dark blue, almost purple color. It is 
hard, and solid in structure, but can be broken readily, and 
has a tendency to break in cubes or square pieces. It is 
soluble in water, and has neither taste nor smell. 

Indigo is used in the dying of silk, linen, woolen and 
cotton goods. It is also a very important ingredient in 
some of the most valuable paints, and also in some of the 
blue and black inks. It is used for laundry purposes. Large 
quantities are consumed annually for manufacturing, etc. 

Remarks on the cost, uses, etc., of indigo. 


THE TEACHER'S AID. 


259 


CORK. 

Cork is the bark obtained from the cork oak, commonly 
known as the cork tree. This tree is an evergreen and 
attains a height of from twenty to fifty feet. The fruit, 
which is eatable, is in the form of acorns, and in taste 
resembles the chestnut. 

The bark of the tree has a soft, spongy, fungous-like 
appearance, and grows in layers from the inner side; and 
as the outer bark is distended by the inner growth, it 
cracks and finally drops off in flakes. This is the natural 
process by which the old bark is replaced by the new. 

It was discovered that the bark of the tree could be cut 
and removed without injury to the tree, as it readily 
produced another bark. The bark obtained in this way is 
much superior to that cast off by the natural growth of the 
tree. Therefore, the cork of commerce is cut, and removed 
from the tree, a year or two sooner than the bark would 
naturally fall off. 

This process is repeated every six or seven years. The 
bark is not removed in to the wood; only the older, outer 
layers that have lost their vitality and are not essential to 
the life of the tree, are removed. The inner bark develops, 
and is removed the same way. Some trees continue to 
yield crops of bark for a century, or even longer. To 
remove the bark it is cut in longitudinal and transverse 
directions. The incisions being made to the proper 
depth, the pieces of bark are then removed with a curved 
knife having two handles. The bark is then soaked in 
water and pressed to remove the curved shape, and dried. 

The pieces of bark are then charred, to remove any 
decayed portions and conceal any defects. These pieces 
are then cut into strips, and the strips into squares of 
various sizes, and made into corks for stopping bottles, 



260 


THE TEACHER’S AID. 


casks, jugs, etc; they are cut by hand and machine^, and 
require very sharp knives and instruments. Although cork 
is a soft substance, it readily dulls a knife and requires the 
frequent sharpening of the tools used. Only the best grade 
of knives can be used. 

Cork is a light, porous substance, of a lightish color. It 
can be bleached white, and dyed various colors. Besides 
being used as stoppers, it is used in the construction of life- 
preservers, floats, buoys, etc., on account of its lightness 
and the difficulty with which it can be sunk in water. It is 
used for packing around glass, bottles and articles that are 
easily broken. Also, for inner soles for shoes, as it prevents 
the shoe from absorbing moisture. Burnt cork, or Spanish 
black, is used by artists. The cork oak is found in the 
southern part of Europe and the northern part of Africa. 
The various uses for cork are seen in our every-day life. 
The small cuttings are not wasted, but are ground up and 
used as a packing. It is used as a deadening substance 
between floors and walls. 

Note: Remarks on cost, uses, etc., of cork 

& £ & 

ASBESTOS. 

Asbestos is a mineral consisting chiefly of silica, lime, 
magnesia, and oxide of iron. It is composed of long, 
delicate fibres, and is usually of a white or grayish color; 
sometimes, however, it is composed of compact, fibrous 
masses of a greenish or reddish shade. These fibrous 
masses are elastic and flexible, and sometimes very easily 
separated. There are several varieties of asbestos. 

Rock-cork is a variety which very much resembles cork, 
is soft and very easily cut; it is so light that it will float 


THE TEACHER'S AID. 


261 


on water. Rock-leather and rock-wood are varieties very 
similar to rock-cork, but much heavier. 

It is incombustible, and cannot be destroyed by fire, and 
for this reason it is used in the manufacture of iron fire¬ 
proof safes, the linings of ovens, for the walls of rooms, for 
lampwicks, and for stove mats. It is also used as a packing 
for water pipes, to protect them from either the heat or the 
cold, and in the manufacture of gloves and cloth. 

It was formerly used as a shroud for dead bodies, and has 
been recommended as a suitable material for the manu¬ 
facture of firemen’s clothing. Only the finer varieties are 
made into cloth. 

Asbestos is the only mineral that is not affected by heat 
or fire. It does not melt, and is not consumed by either 
heat or fire. It is insoluble in water, but can be dissolved 
in strong acids. 

Asbestos is a non-conductor, and for this reason gloves 
made of this substance are used by electricians. Cloths 
which are made of asbestos are cleaned by being placed in 
the fire and brought to a red heat. When removed from 
the fire they are perfectly clean, all dirt having been 
removed by the action of the fire, and the cloth uninjured. 

Asbestos is obtained in North America, Tasmania, New 
South Wales, and in the Alps and Pyrenees mountain 
regions. It is a rather expensive product, and is not in 
very general use. 

Note: Remarks on cost, uses, etc., of asbestos. 

COTTON. 

Cotton is a soft, downy substance, in appearance very 
much like soft wool. It is obtained from the pods of the 
cotton plant. This plant is found in various parts of the 


262 


THE TEACHER'S AID. 


globe, but usually in the tropical regions of America, Asia 
and Africa. Its cultivation has been introduced into the 
temperate zones. There are a great many varieties of the 
cotton plant. They are annual or perennial, and are 
partly shrubby and partly herbaceous. 

The leaves of the cotton plant are from three to five 
lobed, and when quite young they have dark or black 
points. In some varieties the leaves and stems are smooth, 
while in others, as the American cotton, the stems and 
leaves are hairy. 

The flowers, which are large, and usually yellow, though 
in some kinds purple, grow singly from the axils of the 
leaves, and are encased at the base by three large, heart- 
shaped, green leaves, which grow together as one leaf. The 
flowers remain in bloom only a short time. 

The fruit is a large, oval, three or five-celled pod, which 
springs open when ripe. This pod contains the cotton, 
which is usually white, but sometimes yellowish, and which 
springs from the pod as soon as it bursts open. Within 
the cotton are found many seeds, which are either green or 
black, according to the variety of the cotton. 

The cotton plant is very tender, and requires a peculiar 
soil, suitable climate, the proper amount of heat and 
moisture, and the necessary amount of cultivation and 
care, in order that it may be properly developed and 
matured. 

Frost or cold weather are injurious to it, as is also 
excessive drouth and heat, or too much moisture at certain 
stages in the growth of the plant. The most perfect mode 
of cultivation is that in use in the United States. 

The land is usually prepared in the winter months, and 
as soon as the danger of frost is past in the spring, the 
ground is marked off in rows from three to four feet apart, 
varying according to the quality of the soil and the location. 


THE TEACHER'S AID. 


263 


The seeds are sowed in straight furrows, and after the 
plants have come up they are thinned to the desired dis¬ 
tance apart. In some cases the seeds are planted from 
twelve to eighteen inches apart, thus avoiding the work of 
thinning the plants. Eight or ten days after the planting, 
if weather and circumstances are favorable, the plants 
appear above the ground. 

The plant begins to bloom about the latter part of May, 
or the first of June. The flowers soon fall off, and are 
succeeded by the pods, which grow and develop during the 
months of June, July and August, when the picking of the 
cotton begins. As the plant yields a succession of blos¬ 
soms, the ripening of the pods occurs in succession, and 
continues until the frost stops the growth and development 
of the plant. 

The cotton is gathered and placed in bags or baskets, 
which are suspended from the shoulders of the pickers. 
When the picker has gathered as much as he can con¬ 
veniently carry, the bag or basket is emptied and the 
process is repeated. Owing to the manner in which the 
cotton crop ripens, the field has to be picked over many 
times. A cotton field presents a beautiful appearance, 
with the green leaves and white cotton balls intermingled. 

When the crop is gathered, it is spread out and dried, and 
when thoroughly dried the seeds are removed by means of 
the cotton gin, or mill. It is then packed in bales of a 
uniform size and weight, and in this form is ready for the 
market. 

Cotton forms a useful and important article in the 
manufacture of cloth. In the manufacture of cloth it is 
frequently mixed with silk and wool. In this way a more 
expensive cloth is made than if all cotton was used, and a 
cheaper article than if made of all silk or wool. These 
combinations with silk and wool are extensively manu- 


264 


THE TEACHER’S AID. 


factured. It has also other uses, as for packing, gun 
wadding, surgery, etc. 

Various uses are made of the seed of the cotton plant. 
These seeds contain a large quantity of oil, which is used for 
a great many purposes. The oil is obtained by grinding the 
seeds and pressing the oil out. Many tons of seeds are used 
annually for this purpose. Cotton-seed meal, or cake, 
makes an excellent food for stock, as it is rich in nutritious 
matter. When cattle are fed on this substance they 
fatten rapidly and yield extremely rich milk. The cotton 
seeds and meal are also extensively used as a fertilizer. 
Great quantities of seeds are used annually for seeding 
purposes 

Note: Remarks on cost, cultivation, uses, etc., of 
cotton. 


TAPIOCA. 

Tapioca is the product of Manioc, Mandioc, or Cassava, a 
large, half shrubby plant. This plant is a native of tropical 
America, and much cultivated there. It is now also 
extensively cultivated in Africa, and has been introduced 
into other tropical countries. 

The plant grows in bushy form, with the stem usually 
from six to eight feet high, but sometimes more. The 
stems are white, brittle, and have a very large pith; the 
branches are crooked. The leaves, which are near the 
extremities of the branches, are large and deeply seven- 
parted. 

The roots are very large, turnip-like, sometimes weighing 
as much as thirty pounds; from three to eight growing in a 
cluster, usually produced by a root two feet long. 

The root, grated, dried on hot, metallic plates, and 


THE TEACHER'S AID. 


265 


thoroughly powdered, becomes an article of food very 
largely used in South America. It is made into cakes, 
which are formed, not by the assistance of water, but by the 
action of heat softening and agglutinating the particles of 
starch. It is also imported into Britain to be used in the 
manufacture of starch. 

The true starch of Manioc, separated in the ordinary 
manner from the fibre, is also imported in considerable 
quantity into Britain under the name of Brazilian arrow- 
root, and from it tapioca is made by heating it on hot 
plates and stirring it with an iron rod. The starch grains 
burst, some of the starch is converted into dextrine, and the 
whole amalgamates into small, irregular masses or grains. 

Note: Cost, uses, manufacture, etc., of tapioca. 

j* j* 

EBONY. 

Ebony is a wood remarkable for its hardness, heaviness, 
and deep black color. The name is also sometimes applied 
to the black woods of other trees that are very different 
from those which produce the true ebony. 

Ebony is the heart-wood of the trees which produce it. 
Some of these trees grow to such great dimensions that logs 
of their heart-wood measuring two feet in diameter and 
varying from ten to fifteen feet in length can easily be 
obtained. 

The best quality of ebony is that which excels in uni¬ 
formity and intensity of color. This quality is the product 
of a tree that abounds in some of the flat parts of Ceylon. 

In Madagascar, ebony of very good quality is obtained. 
There are other species which are very much valued for 
their beautiful wood, the prevailing color of which is black, 


266 


THE TEACHER'S AID. 


striped with a rich yellow-brown; but the density and 
durability of this wood is very inferior to the real ebony. 

Ebony is chiefly used by cabinet makers for veneering. 
It was used by the ancient Greeks and Romans, who 
frequently inlaid it with ivory to make a contrast of color; 
and in this way it was used for ornamental purposes. The 
ancients presumably obtained it from India and Mada¬ 
gascar. 

Ebony is susceptible of a remarkably good polish, and is 
a very hard and durable wood, and much used by the 
manufacturers of musical instruments. 

It is an important article of export from the West 
Indies. But the trees from this locality are of small size, 
attaining an altitude of only from twelve to fifteen feet, and 
only a few inches in diameter. The wood of the American 
or West Indian ebony tree is of a greenish-brown color, 
instead of a black. 

Ebony was at one time used medicinally, as a laxative 
and sudorific; it has a very pungent taste. 

Note: Remarks on cost, uses, etc., of ebony. 

& 

LARD. 

Lard is the pure fat of the hog. It is obtained by “ren¬ 
dering ” or melting the fatty parts of the flesh by the appli¬ 
cation of heat. Until the end of the first quarter of last 
century lard was exclusively used for culinary purposes 
and as the basis for different ointments in medical use. 

The extent to which hogs were raised, however, made it 
necessary to find some other use for such a valuable article, 
and large quantities were pressed at a low temperature, by 
which means the stearine and oleine were separated. 

The stearine was used in the manufacture of candles, 


THE TEACHER'S AID. 


267 


and the oleine, under the name of lard-oil, soon became a 
very important article of commerce. It became a valu¬ 
able lubricant for machinery. 

The operation by which lard is now obtained is per¬ 
formed by placing the fatty portions, after they have been 
cut into very small pieces of an almost uniform size, in a 
large, heavy iron kettle or boiler. 

A little water is usually placed in the bottom of the 
kettle in order to prevent the fat from adhering to it. A 
moderate heat is applied under the kettle and continued 
until all the fat has been cooked or melted out of the fatty 
particles and only a dry crutling remains. 

The kettle is then withdrawn from the heat, or the heat 
removed from the kettle, according to which may be the 
most convenient. The melted fat is allowed to become 
partially cool and is then strained through a coarse cloth or 
sieve into jars or wooden kits and allowed to become per¬ 
fectly cold. It assumes a fairly solid consistency when 
cold, but readily becomes a liquid oil again on the applica¬ 
tion of heat. 

When packed in the jars and kits it is then in the form 
known as the lard of commerce, and in this condition will 
keep for an indefinite time in a moderate temperature. 

Note: Remarks on cost, uses, etc., of lard. 


BRASS. 

Brass is an alloy made by the combination of copper 
and zinc, about one-third usually being zinc, but the pro¬ 
portions vary somewhat. The best brass is made by cemen¬ 
tation of calamine or the oxide of zinc, with granulated 
copper. 

It is a hard, yellow metal and susceptible of a very high 


268 


THE TEACHER'S AID. 


polish. Commonly speaking, the term “ brass ” is extended 
so as to include compounds which are made of copper and 
tin; but properly speaking, brass includes only the alloys 
of copper and zinc, or yellow brass. 

In the manufacture of brass in large quantities, two 
parts, by weight, of copper to one of zinc are the propor¬ 
tions used; but for practical purposes a quarter or less 
proportion of zinc is taken. 

When a metal of more than ordinary tenacity is desired 
the amount of zinc is reduced to one-fourth of the weight 
of the copper used; and when an alloy of a hard, brittle 
consistency, with very little resisting power, is required, an 
equal amount of zinc and copper are used; or in some cases 
the zinc is made greater than the copper. 

In the manufacture of brass the zinc is fused in a crucible 
and the copper gradually added in pieces. But this opera¬ 
tion has its disadvantages, owing to the volatile nature of 
of the zinc and its tendency to oxidize. 

An indirect method of obtaining brass is one which is 
generally adopted in England and elsewhere and is as fol¬ 
lows: A mixture of carbonate of zinc, charcoal and thin 
pieces of scrap or grain copper, are heated in crucibles or 
pots. 

The mixture is usually roasted in order to expel an}/ 
traces of sulphur that may be in the metals; it is next 
mixed with one-fourth of its weight of charcoal. It is then 
turned into a crucible, after which the metallic copper is 
diffused throughout the mixture by being beaten with 
hammers and mallets. 

The proportions used are three parts of cabonate of zinc 
and charcoal to two parts of copper; this mixture is placed 
in a furnace and subjected to a white heat for from five to 
twenty-four hours, during which process the charcoal 
reduces the carbonate of zinc and also separates the zinc, 


THE TEACHER’S AID. 


269 


which unites with the copper and forms brass in the pro¬ 
portion of two parts of copper and one part of zinc, and is 
now in the form of brass in the bulk. 

For ordinary purposes brass is cast into sheets or plates 
which weigh about one hundred pounds. These plates 
vary from one-fourth to one-half inch in thickness and can 
be easily broken or melted, and then cast in moulds and 
made of any desired size or shape. 

The castings thus obtained, when intended for use or 
for the manufacture of articles, are usually screwed to a 
turning-lathe and turned or bored into the required shape 
with iron tools. 

Brass is used in the manufacture of knobs for doors and 
window fastenings, gas and water fixtures, brackets, pend¬ 
ants, band instruments, fittings and fixtures for different 
kinds and parts of machinery, castings, bells, foundry and 
plumbers’ goods, stamped goods, wire, sheeting, lamp¬ 
making, naval supplies and many other useful and orna¬ 
mental articles. 

Brass was evidently one of the earliest metals used by 
the ancients, as reference is made in the early Biblical and 
profane history in relation to the construction of musical 
instruments, ornaments, implements, various kinds of ves¬ 
sels, gates, etc., from this metal. 

No mention is made, however, of the method by which 
the brass of the ancients was manufactured or the compo¬ 
sition and proportion of the ingredients used. 

Large quantities of brass are used annually in the manu¬ 
facture of machinery, fittings, gas fixtures, plumbers’ goods, 
etc., etc. Many of these brass goods are very expensive, 
while others do not cost so much. 

Note: Remarks on cost, uses, manufacture, etc., of 
brass. 



270 


THE TEACHER'S AID. 


BRONZE. 

Bronze is an alloy formed wholly or chiefly of tin and 
copper, in proportions that vary; other metallic substances 
are sometimes added to the tin and copper, zinc being the 
chief one used in combination. 

This metal has been known and used from a very early 
period, and what was referred to as brass by the ancients 
was in reality bronze. 

The brass or bronze referred to in the Bible was doubt¬ 
less composed of copper and tin, although translators sup¬ 
pose it to have been made of copper alone. Historical 
researches and the examination of the most ancient coins, 
metallic ornaments and implements leaves no doubt as to 
the use of brass by the ancients. In fact, the use of brass 
was so common that in the antiquarian history of European 
nations there is a distinct period which is known as the 
bronze period. 

In the preparation of the various kinds of bronze great 
care had to be taken to prevent the tin from being burned 
away or wasted, and in order to obviate this large quan¬ 
tities of old, worn-out brass, such as old cannon, etc., are 
fused in a furnace and the fresh, new copper and tin added. 

For the better grades of bronze the best Cornish and 
Banca tins are used, especially if a strong alloy is desired; 
for inferior grades old scrap tin, which often contains lead, 
is used; and where no particular strength is required in the 
alloy, a little zinc and lead are sometimes added. 

The metals to be used are mixed and fused in a furnace 
at a high temperature, during which time as little air as 
possible should be admitted to the furnace, as contact with 
the air oxidizes the metals and is detrimental to the alloys 
and thereby produces an inferior quality. 

When bronze of a good quality is obtained its durability 


THE TEACHER'S AID. 


271 


is next to gold, platinum and some of the other rare metals. 
Its durability and extreme hardness combined enables it to 
stand a great amount of wear, for which reason medallions, 
etc., designed to be inscribed and ornamented were made 
of bronze, and for this same reason France issued a bronze 
coin to take the place of the copper one; the same has also 
been done in Great Britain. 

Bronze is used in the manufacture of common toothed 
wheels, mathematical instruments, for the bearings of 
machinery, bells, musical bells, cymbals, gongs, telescopes, 
mirrors, statues and many other articles both useful and 
ornamental. 

By means of a recently discovered electrotype process, 
bronze can be deposited over the surface of objects in a 
coating of different degrees of thickness. In this way orna¬ 
ments, statues, etc., can be made for a much less price than 
when made of the solid bronze. The galvanizing or plating 
process has also been suggested as a coating for the parts 
of machinery that are liable to rust. 

Bronze is also the name applied to a compound prepared 
for the purpose of imitating the metal bronze. It is of two 
kinds and is known as yellow bronze and red bronze; the 
yellow variety is made of fine copper dust, and the red of 
copper dust with a mixture of pulverized ochre. These 
bronzes are obtained in the form of a fine powder. 

Bronzing is the process by which these compounds are 
applied to the surface of objects made of metal, plaster, 
stone, clay, etc., in order to make them appear as if made 
of bronze metal; it has a very pleasing and in many cases a 
very durable effect. 

Bronze powders are manufactured in many different 
colors and shades, and are applied in various ways; they 
all produce very beautiful and pleasing effects. 

They are usually mixed with some kind of oil having 



272 


THE TEACHER'S AID. 


good drying properties, and applied with a brush, one or 
more applications being given to the object to be bronzed. 

The manufacture of bronze colors or powders is carried 
on to a great extent, and large quantities are consumed 
annually; they are usually very inexpensive. 

Note: Remarks on manufacture, cost, uses, etc., of 
bronze metal and bronze. 

jft, jt 

TILES. 

Tiles are pieces of baked clay, slag, glass, etc., which are 
used for building and paving purposes. They are of vari¬ 
ous sizes according to the use to which they are to be 
applied; some are used for walls, some for roofs, some for 
pavements, floors, stairs, etc. 

The finer kinds of paving stones are known as encaustic 
tiles and are used in very fine buildings, walks, pavements, 
etc. The smaller cubical pieces are used for mosaic pur¬ 
poses, and with them are made many very artistic and 
beautiful designs. 

Besides being beautiful and artistic for use in halls, 
stairs, etc., they are very durable and are easily kept clean. 
Some varieties are quite expensive, while others are very 
inexpensive. 

These tiles can be colored and tinted any desired color 
or tint, and when thus colored and laid in pretty patterns 
they produce a very beautiful and striking effect. 

On the side that is intended to be uppermost they are 
given a high polish, which they retain even when given 
constant use. They are especially designed for floors and 
walks in public buildings and walks where there is a great 


THE TEACHER'S AID. 


273 


deal of traffic. Designs of birds, animals, flowers, etc., are 
wrought with these tiles. 

Note: Remarks on cost, uses, manufacture, etc., of 
tiles. 

jt 

MOROCCO LEATHER. 

Morocco leather is a fine kind of leather, commonly pre¬ 
pared from goat skin, although an inferior quality is made 
from sheepskin tanned with sumac. The manufacture of 
morocco leather is said to have originated with the Moors. 

It was formerly an article of import from the Barb ary 
States, but it is now prepared in large quantities in almost 
all countries. It is always dyed or colored on the outer or 
grain side, and the leather-dresser, in finishing, gives a 
peculiar granulated or ribbed surface to it. This is done by 
means of engraved boxwood balls, which he works over the 
surface of the leather. 

In the production of leather, the Moors far surpass the 
Europeans. They are able to render any kind of leather 
soft and white. This is supposed to be done by the use of 
two kinds of plants which are unknown to Europeans. 
They also excel in the production of brilliant colors. 

Leather can be colored any desired color or shade. 
Morocco leather is a very durable leather, and in many 
cases it is very expensive. 

It is used in the manufacture of various kinds of leather 
goods, in the upholstering of furniture, for book-binding 
purposes, etc. 

Note: Remarks on cost, uses, etc., of morocco leather. 

18 


274 


THE TEACHER’S AID. 


ESSENCES. 

Essences are the volatile or essential oils which exist, in 
most instances, ready formed in plants, and believed to 
contribute to their odorous principles. They are the pre¬ 
dominant qualities or virtues of any plant or drug, 
extracted, refined or rectified from grosser matter; or, more 
strictly speaking, a volatile oil, perfume, odor or scent. 

They form an extensively numerous class, most of the 
members of which are in the fluid form; a few, however, 
are solid at ordinary temperature, but all of them are cap¬ 
able of being distilled without undergoing change. 

These oils have characteristic, penetrating odors, which 
are seldom as pleasant as those of the plants from which 
they are derived; their taste is hot and irritating. 

The greater number of them are derived from, or are the 
product of the vital activity of plants, in which most of 
them exist ready-formed; they are enclosed in minute 
cavities or sacs, which are often visible to the naked eye. 

In the comparatively few cases in which these oils are 
not found naturally formed they are produced by a process 
of fermentation, as the product of dry distillation or of the 
putrefaction of many vegetable bodies. 

The essential oils are much used in the manufacture of 
perfumeries, for flavoring confectionery, liquors, etc., and 
for various purposes in medicine and the arts. 

Some of these essences are quite expensive, while others 
are comparatively inexpensive. The manufacture of the 
various essences forms a very important industry. 

Note: Remarks on cost, uses, production, etc., of 
essences. 


THE TEACHER’S AID. 


275 


CREAM OF TARTAR. 

Cream of tartar is the purified cream of argol, or the 
bitartrate of potassa, so called because is rises like cream 
to the surface of the liquor in which it is purified. 

It is a colorless, transparent salt, crystallizing in four¬ 
sided prisms. It exists naturally in grape juice, but being 
insoluble in alcohol it is gradually deposited in the form of 
argol as the sugar of the juice becomes converted into alco¬ 
hol by the process of fermentation. 

Cream of tartar is also the crust or deposit formed by 
wine in bottles or casks in which it is fermented. The red 
wines are usually richer in argol than the white varieties. 

A ton of grape wine yields, according to the nature of 
the fruit, quantities varying from one to twelve pounds of 
argol, and of this, when the samples are good, eighty-three 
per cent is cream of tartar. 

In the manufacture of cream of tartar the argol is dis¬ 
solved in hot water at a high temperature; to this solution 
of water and argol is added a quantity of charcoal and 
fine clay, which absorbs the coloring matter. 

The liquor is boiled and filtered, and after two or three 
days, during which time the insoluble impurities subside, 
the pure liquid, in the form of a clear, colorless solution, is 
drawn off into earthen vessels. 

As the liquid cools, the cream of tartar separates in the 
form of pure crystals, some of which settle to the bottom, 
while others form a crust-like cream on the top. The solu¬ 
tion is then run into conical coolers or tanks, where, at the 
end of eight or nine days, the sides of the vessels become 
coated with fine, clear crystals; all coloring matter has been 
removed by the charcoal and clay. The crystals are then 
bleached and dried by exposure to the sunlight and air. 

In regard to its chemical composition, cream of tartar is 


276 


THE TEACHER'S AID. 


known as bitartrate of potash and consists of potash, water 
and tartaric acid. 

Cream of tartar readily dissolves in hot water, although 
it takes sixty parts of cold water to dissolve one part of the 
cream of tartar. 

When the process of manufacture is completed it is in 
the form of a white powder, having a strong acid taste and 
a gritty feel, and in this form it is known as the cream of 
tartar of commerce. 

Cream of tartar is used for culinary purposes, as in the 
raising of cakes, biscuits, etc.; in medicine as a refrigerant 
diuretic and a mild purgative; in dyeing operations as a 
mordant for wool; in the manufacture of tartaric acid, 
and with powdered alum and chalk as a preparation for 
cleaning silver, etc. 

Remarks on uses, etc., of cream of tartar. 

jt & 

MIRROR. 

A mirror is a looking-glass or speculum, or a glass or 
polished surface that forms images by reflection of rays of 
light. They are usually made of glass, lined at the back 
with a brilliant metal so as to reflect plainly the image of 
any object placed before it. 

It is not known just when mirrors were invented, but the 
use of a reflecting surface would become apparent to the 
first person who saw his own image reflected from the water, 
and possibly after the civilization of man commenced, the 
still waters of ponds and lakes were the only mirrors. The 
Indians used ponds and rivers as mirrors, but we also read 
that in Bible times there were mirrors of brass. 

Mirrors of glass were first manufactured in Venice in 
1300, and judging from those in existence they were very 


THE TEACHER'S AID. 


277 


imperfect articles as compared with the modern ones of the 
present day. 

It was not until about 1673 that the manufacture of 
mirrors was introduced into England. But it is now a very 
important manufacture in almost all countries. Mirrors 
can be produced in any size to which plate glass can be cast. 

After the plate-glass has been cast and polished on both 
sides it is laid on a perfectly level table of great strength 
and solidity; this is usually made of stone and has raised 
edges like a billiard table. 

Tin foil of sufficient size to cover the glass on the upper 
side is laid on and rubbed smooth, after which it is covered 
with quicksilver, which immediately forms an amalgam 
with the tin. 

The superfluous mercury is then run off, and a woolen 
cloth is spread over the whole surface and square irons laid 
on as weights to keep the glass straight and level. After 
this pressure has been continued for a day and night, the 
weights and the cloth are removed and the glass placed 
upon another table made of wood. 

This table has a movable top and admits of being gradu¬ 
ally inclined until the unamalgamated quicksilver has per¬ 
fectly drained off and only the surface of perfect amalgam 
remains as a coating for the glass and perfectly adherent 
to it. 

Mirrors of bronze were used by the ancient Egyptians, 
Greeks and Romans, and many specimens of their mirrors 
are to be found in museums. Silver was used in the manu¬ 
facture of mirrors three hundred years B. C. 

Mirrors are chiefly used for ornamental purposes. They 
vary in size from the tiny ones that cover only an inch in 
surface to the very large ones that cover many yards of 
surface. They are usually encased in frames, some of which 


278 


THE TEACHER’S AID. 


are very costly and beautiful, while others are very plain 
and cheap. 

In many instances they are set in walls and panels for 
decorative purposes, in both private and public buildings. 
In some cases the silver coating wears off the back of the 
glass or becomes dim or scratched, and when this occurs 
the entire coating can be removed and the glass re-coated. 

As heat is reflected like light, a concave mirror may be 
used to bring rays of light to a focus, and by the use of 
these concentrated rays of light combustible materials may 
be ignited at a great distance from the mirror or reflecting 
surface from which the rays of light receive their heat. 
When a mirror is thus made use of it is called a burning 
mirror. Some mirrors are very expensive, while others are 
inexpensive. The cost depends on .the quality and thick¬ 
ness of the glass, on the time and labor expended in the 
manufacture, and in the kind of coating used on the back 
of the mirror. 

Note: Remarks on cost, uses, manufacture, etc., of 
mirrors. 

MAGNESIUM. 

Magnesium is a metal which is generally ranked with 
those whose oxides form the alkaline earths, but in many 
respects it more closely resembles zinc. 

It is a malleable, ductile metal, of the color and brill¬ 
iancy of silver. It is obtained from its chloride either by 
the action of sodium or potassium or by simple electrolytic 
decomposition; but the ordinary processes are difficult and 
yield the metal in minute quantities. 

A patent has, however, been taken out for improvements 


THE TEACHER'S AID. 


279 


in its manufacture, by which it can be produced in much 
greater quantities. 

The common magnesia is the only oxide of magnesium. 
It is a whitish, bulky powder, devoid of taste or smell. It 
is infusible and almost insoluble in water. 

Magnesia does not occur native, but is usually obtained 
by the prolonged application of heat and carbonate. Many 
of the compounds of magnesia are employed in the prepa¬ 
ration of medicines. The principal compounds of mag¬ 
nesia used medicinally are magnesia, its carbonate and its 
sulphate; it is used as a laxative, and when combined with 
senna forms the well-known black draught. 

It is also used in the production of magnesium light, 
which in color approaches very much nearer daylight than 
the light of oils, candles, coal-gas, etc. In photography it 
is used to take pictures or views of dim or underground 
structures; it is wholly used for burning in photographic 
lamps for “flash-light’ 7 pictures and for fire-works. This 
light does not, hoAvever, compare with electric light, as now 
perfected. 

Note: Remarks on cost, uses, etc., of magnesium. 

MOTHER-OF-PEARL. 

Mother-of-pearl is a hard, brilliant substance, which 
forms the inner layers of shells of several kinds of large 
bivalve mollusc, which also produce the precious pearl. 

The interior of our common oyster shell is of this nature, 
but the mother-of-pearl used in the arts is much more 
variegated with a play of colors. The large shells of the 
Indian seas alone have this pearly substance of sufficient 
thickness to be of any material use. 

These shells are collected in great numbers in the trop- 


280 


THE TEACHER'S AID. 


ical seas, chiefly on the coast of Ceylon, Manilla, Cuba, 
Panama and the South Sea islands. 

Large quantities of these shells are consumed in inlaying 
fancy wood-work, papier maehe and in making knife- 
handles and other small ornamental objects. But by far 
the greater proportion is used in the manufacture of pearl 
buttons. 

Note: Remarks on cost, uses, etc., of mother-of-pearl. 

j* £ j* 

WIRE. 

Wire is a metallic substance drawn to a thread. Most 
metals possess this property to a greater or less degree. 
Antimony and bismuth are so very brittle that it is with 
difficulty they can be drawn into wire, and their wire, for 
lack of tenacity, has little value. 

Iron, copper, brass and other metals largely used in the 
manufacture of wire are drawn and finished in much the 
same way. In making wire, sheets of the metal to be used 
are cut up in strips and drawn into wire by forcing it 
through the holes of draw-plate. 

This plate consists of an oblong piece of hard steel 
pierced with conical holes, gradually diminishing in size 
and having the smaller ends of the holes regulated to the 
required size of the wire, and as the drawing proceeds, the 
wire is coiled round a cylinder. 

After being once drawn, it is again passed through a 
smaller hole, and this process repeated until it has been 
reduced to the desired size. Very fine wire may require 
from twenty to thirty drawings. 

After having passed a few times through the draw- 
plates, the metal becomes brittle and requires to be 


THE TEACHER’S AID. 


281 


annealed. For very fine wire a lubricating substance, such 
as grease, soap or wax, is used. 

For very accurate purposes, such as chronometers, the 
wire is drawn through jeweled holes, that is, holes perfo¬ 
rated through rubies and other hard gems. 

Although mostly cylindrical, wire is drawn in many 
shapes, such as oval, half-round, flat, triangular, moulded 
and grooved. Copper wire of different forms is used to 
make patterns on the blocks used for printing calico. Steel 
and iron wire are used in the manufacture of nails, screws, 
needles, fish-hooks, hooks and eyes and many other articles. 
Brass wire for pins, chains, wire-cloth, etc.; iron and copper 
wire for the electric telegraph; steel wire for the manufac¬ 
ture of ropes; gold and silver wire for laces, cloth, orna¬ 
ments, etc. 

Gold can be drawn into wire only one five-thousandth of 
an inch in thickness; platinum wire to one three-thou¬ 
sandth of an inch when the ores in the form of bars have 
first been coated with silver. The silver can then be 
removed by the use of nitric acid. 

Metals are ductile in the order of their malleability, or 
nearly so, the order of their ductility being as follows: 
Gold, silver, platinum, iron, copper, zinc, tin, lead, nickel 
palladium and cadmium. 

Remarks on the uses, manufacture, etc., of wire. 

jt 

FLAX. 

Flax is an annual or a perennial plant, of which there 
are about ninety varieties known. These are scattered 
over the globe, but are most abundant in Europe and the 
northern part of Africa. 

This plant is not only valued for its fibre or inner bark, 


282 


THE TEACHER’S AID. 


but for its seeds. The fibres of the inner bark, when sep¬ 
arated from the bark and from the woody portions of the 
stems, are known as flax or lint. It is from this fibre that 
the well-known linen cloths and threads are made. Linen 
is made into the finest as well as the coarsest of fabrics, 
from the most delicate cambrics and exquisite laces to the 
coarsest and strongest kinds of sail-cloths. 

The seeds of the flax plant, when pressed, yield a fixed 
oil called linseed oil. This oil possesses great drying qual¬ 
ities and is largely used in mixing paints and varnishes. 
The crushed mass of seeds that is left after the oil has been 
expressed is known as linseed cake or oil cake. This cake 
is greatly valued as a food for cattle, and when ground to 
a fine powder it is known as linseed meal and is much used 
in the making of poultices. Linseed is also frequently used 
medicinally. No other plant, not yielding food, is of more 
use to man than the flax plant. 

When the crop has matured it is always pulled up by 
the root, instead of being cut, as almost all other similar 
crops are. The best time for gathering the crop is when 
the seeds are beginning to change from a green to a pale 
brown. If the crop, when mature, is of different lengths, 
the lengths, when pulled, should be kept separate, as uni¬ 
formity in this respect is of great value and convenience in 
the processes to which it is afterwards subjected. 

After the flax has been pulled and sorted into lengths 
the next process is known as rippling; this consists in 
removing the balls, or seed-pods, from the stalks. 

This is accomplished by drawing the stalks through a 
series of iron teeth, which are about eighteen inches long, 
and placed about a half an inch apart. These teeth are 
fastened in blocks of wood, which are placed at the ends of 
planks or long stools on which the workmen are seated. 

The next process is separating the flaxen fibre or lint 


THE TEACHER'S AID. 


283 


from the woody core or bone of the stem. In order to do 
this the stems of the plants are tied in bundles and steeped 
in water until the bone or woody parts begin to rot, in 
which state the fibre and bone are easily separated. This 
operation is called rotting, or retting, and should be con¬ 
ducted with great care. 

After being sufficiently steeped, the flax is spread on the 
grass in order to correct any defect in the retting. 

In some instances it is the custom to conduct the retting 
process entirely on the grass; this process is known as dew- 
retting to distinguish it from water-retting. By another 
method the flax is placed in tanks or vats, in which it is 
held down by the use of a strong iron frame-work. Water 
is next turned into the vat, and enough only is used to be 
absorbed by the flax. 

Steam is next applied, and acetuous fermentation takes 
place in a few hours, and the decomposition of the green 
matter in the stalk is soon completed. The water is with¬ 
drawn from the vat and the flax taken out, separated and 
dried either in the air or in drying-rooms. 

By another process the flax is placed in a vessel pro¬ 
vided with a perforated false bottom; the top is double and 
filled with water so as to act as a condenser. Steam is then 
admitted to the case, which results in freeing the flax from 
certain volatile oils. It takes about thirty-six hours to 
complete the process. The flax is then taken out and 
passed between rollers in the lengthwise direction of the 
stems. These rollers press the water out and decompose 
the gum, and split and flatten the stems. 

If prepared by either of these processes the flax is now 
ready to be entirely freed of all its woody particles. This 
is effected by a process known as scutching. But just 
before it undergoes this process the flax is run through 


284 


THE TEACHER'S AID. 


revolving rollers in order to completely break the hard 
parts on the inside of the fibre. 

After passing through the breaking machine the flax- is 
next acted upon by a series of knives attached to the arms 
of a vertical wheel; these knives are set so as to strike the 
flax stems in the lengthwise direction, and for this reason 
they separate the fibres, but do not cut them. This process 
is repeated three times before the flax is thoroughly sepa¬ 
rated and ready for use. 

•* 

The fibre is next spun into threads and woven into cloth 
in much the same manner in which the silk, woolen and 
cotton fibres are spun'and woven. Linen thread is some¬ 
times interwoven with silk and cotton threads, in which 
case a very durable and beautiful cloth is produced. 

Remarks on cultivation, preparation, etc., of flax. 

OILS. 

Oils and fats are organic compounds, which exist, abun¬ 
dantly in the animal, vegetable and mineral kingdoms. They 
constitute the fats and fixed oils and are very important 
and useful products. 

They are simple organic compounds, but each of them 
is a mixture of several such compounds to which the term 
glyceroids is applied. 

These oils may be solid and hard like suet, semi-solid 
and soft like butter and lard, or fluid like the oils. The 
solid and semi-solid are, however, generally placed together 
and termed fats in order to distinguish them from the fluid 
oils. 

The most solid fats are readily fusible and become 
reduced to a fluid or oily state at a temperature lower than 


THE TEACHER'S AID. 


285 


that of the boiling point of water. All fats and oils are 

lighter than water and are perfectly insoluble in water. 

♦ _ * 

The uses of the oils and fats are numerous and highly 
important. . A great many of the oils and fats are exclu¬ 
sively made use of as articles'of food, as medicine, as lubri¬ 
cating agents, in the manufacture of soaps, plasters, oint¬ 
ments, varnishes, pigments, candles and other means of 
illumination, in the process of dressing leather, etc. 

The fats and oils procured from the vegetable kingdom 
are termed vegetable fats. The chief solid fats of vegetable 
origin are cocoa-nut oil, nutmeg and palm oil. The fluid 
vegetable fats or oils are divisible into non-drying and dry¬ 
ing oils, the latter being distinguished from the former by 
their becoming dry when exposed to the air in thin layers. 

Of the animal fats the chief ones are lard, suet, butter, 
goose-grease, etc., as the solid fats, and among the fluid fats 
or oils are sperm-oil, ordinary whale-oil, coclliver oil and 
neat’s-foot oil. w 

Mineral oils are naphtha, paraffine oil and shale oil. 
Naphtha is a mineral oil, composed of equal parts of car¬ 
bon and hydrogen. It is a volatile, limpid, bituminous 
liquid, having a strong, peculiar odor. It is usually of a 
yellow color and can be made colorless by repeated distilla¬ 
tion. 

It is very inflammable and burns with a bright light; it 
is used for illuminating purposes. It is soluble in alcohol, 
and insoluble in water. 

Naphtha is also known as petroleum and rock-oil. It 
is found exuding from the ground in certain localities. 

Paraffine is a mineral oil obtained by distillation from 
cannel-coal. It is used for illuminating and lubricating 
purposes. It is soluble in hot olive oil, oil of turpentine 
and ether, but insoluble in water. 

Shale oil is a mineral oil obtained from shale or slate 


286 


THE TEACHER'S AID. 


clay. Some shales will yield from thirty to fifty gallons of 
crude oil per ton; but in the process of refining they are 
reduced to about one-half. 

Shale is usually found in coal regions and is often inter¬ 
mixed with the coal, which in many instances it so closely 
resembles that it is sometimes difficult to distinguish 
between the two. 

Shale oil is used for illuminating and lubricating pur¬ 
poses. Shale also produces an oil which dissolves rubber. 
These oils are all obtained by distillation. 

Remarks on uses, cost, preparation, etc., of oils. 

v*6 ^ 

SUGAR. 

Sugar is the name applied by chemists to a number of 
carbo-hydrates which are crystallizable and more or less 
sweetish in taste. The most common sources of sugar are 
the sugar-cane, beet-root and the juice of the maple tree. 

For convenience, sugar is divided into two groups; the 
first is composed of such sugars as are capable of under¬ 
going fermentation and of being changed b}^ the action of 
yeasts either directly or indirectly into alcohol or carbonic 
acid gas. 

The second class includes all sugars which are not capa¬ 
ble of being changed by fermentation into the above 
named product. Cane-sugar, which is the chief sugar of 
commerce, is by far the most important of this group of 
sugars. In sweetening properties cane-sugar exceeds grape 
sugar in a ratio of five to one, and milk-sugar in even a 
greater ratio. 

It dissolves in about one-third of its own weight of cold 
water, producing a thick, viscid fluid; it readily dissolves in 
any proportion of hot water. By the spontaneous evapora- 


THE TEACHER'S AID. 


287 


tion of its watery solution it is deposited in four-sided 
rhomboidal prisms. Common loaf-sugar and sugar candy 
are two well-known forms of this kind of sugar. Grape- 
sugar constitutes the hard, granular masses which are 
found in old dried fruit, such as raisins, etc. 

Glucose or glycose, under which name it is commonly 
known to chemists, is also known as starch-sugar, because 
it is readily obtained by the action of a dilute acid on a hot 
solution of starch. 

Beet-root sugar is manufactured from the freshly-dug 
roots of the sugar beet. The manufacture of this sugar is 
carried on extensively in France, and in this country much 
attention is being given to this kind of sugar. 

In the manufacture of beei>root sugar the juice is 
expressed from the root and is concentrated by being boiled, 
which expels the water. Lime is sometimes added, as it 
neutralizes the acids which are usually present. The 
impurities rise to the surface in the form of scum and are 
skimmed off. 

After having boiled a sufficient length of time, the liquid 
is allowed to cool, and the sugar separates from the 
molasses in the form of grains. The syrup or molasses is 
drained off, and the raw sugar remains. 

In the manufacture of cane sugar the canes are stripped 
of all their leaves and cut; they are then passed through the 
rollers of a press made for this purpose, the greatest pos¬ 
sible pressure being brought to bear upon them. These 
rollers revolve very slowly, the rate being only from two to 
four times per minute, thus allowing ample time for the 
juice to be expressed and to flow off. 

One hundred pounds of cane will yield from sixty-five to 
seventy-five pounds of juice. This juice is of a sweetish 
taste, and the color (*f dirty water; it runs directly from the 
mill into a reservoir placed to receive it. Here it is usually 




288 


THE TEACHER’S AID. 


treated to a small quantity of quicklime and without much 
delay is transferred to large iron or copper vessels; these 
vessels are heated either by a fire beneath, or by steam- 
pipes placed in the liquid. 

As the temperature of the juice is raised, the impurities 
in the form of a thick scum, rises to the surface and is either 
removed by skimming, or the warm juice is drawn off from 
under the scum. The concentration or evaporation of the 
juices is partly effected by being heated in large, open 
hemispherical iron pans. Five or six of these pans, which 
vary in size from six to eight feet in diameter, are placed 
in rows and a fire is kindled under one of the end ones. 

This one fire runs under the whole row of pans; the heat 
is found sufficient to cause two or three of the pans nearest 
the fire to boil rapidly and also to warm the juice in the pans 
farthest from the fire. 

As the juice first enters the pan farthest from the fire, it 
becomes gradually heated, and the vegetable impurities rise 
in the form of a scum to the top and are carefully removed. 
The juice is ladled from one pan to the next, beginning with 
the one farthest from the fire, and boils with greater rapid¬ 
ity as it approaches the fire, and in the pan immediately 
over the fire it seethes and foams with great violence; this 
seems to be an essential part in the successful making of 
sugar. 

The presence of all the impurities, which are removed 
by the scum, interferes with the crystallization of the 
sugar; and the sooner the impurities are removed, the 
sooner the liquid will crystallize into grains of sugar; and 
the rapid ascent of the bubbles of steam through the liquid 
in the pans carries all the impurities to the surface, where 
they can easily be removed by skimming. 

Very great heat is destructive to cane-juice, because it 
turns much of the crystallizable sugar into treacle or 


THE TEACHER'S AID. 


289 


uncrystallizable sugar; but the grain arising from getting 
rid of a large proportion of the impurities in the cane-juice 
more than compensates for the destruction of part of the 
sugar. 

After the concentration has been carried to a given point 
and all the scum has been removed, the application of heat 
is suspended, and the liquid, which is now the color of tur¬ 
bid port-wine, and the consistency of oil is drawn into the 
vacuum-pan, where its concentration is completed at the 
lowest possible temperature. The vacuum pan is in use in 
all sugar refineries and in all well-provided sugar planta¬ 
tions. 

As the crystallization of the liquid in the vacuum-pan 
proceeds, crystals of sugar begin to form, and the skill of 
the sugar-maker is shown by the uniformity of the crystals 
which he produces. 

The boiling is commenced by filling in only about a third 
or fourth of the quantity the vacuum-pan will hold and 
gradually adding more as the crystals increase in size, and 
by the time the vacuum-pan is filled the crystals have 
formed and the contents thickened into a mass of the con¬ 
sistency of thick gruel. It is then transferred to a vessel 
called a heater, where is it simply kept warm until it can be 
run out into the forms. In the ordinary sugar refineries 
these forms generally consist of conical-shaped earthen pots 
which hold from one to two hundred weight of sugar. 
Here the sugar is allowed to cool and complete its crystal¬ 
lization before the plugs, which close the bottom of the 
pots, are withdrawn. 

From one-fourth to one-third of the contents of the pot 
fails to crystallize and remains in a fluid state. When the 
plugs at the bottom of the pots are removed the fluid runs 
off into large tanks placed to receive it; it is again pumped 
up into the vacuum-pan and reboiled, yielding a second 

19 


290 


THE TEACHER’S AID. 


supply of sugar. This reboiling of the drainings is repeated, 
with a constant decrease in the quantity and quality of the 
sugar obtained. This process is rarely carried beyond the 
third or fourth boiling. 

If muscovado, or unclayed sugar, is desired the process 
is now complete, and the sugar is turned out of the forms 
and packed for shipment; but if clayed sugar is to be made 
the forms are allowed to stand for a few days, or until all 
the treacle has drained out; a quantity of thin mud, about 
the consistency of good, thick cream, is poured over the 
sugar to the depth of one or two inches. 

The water which is contained in this thin mud trickles 
slowly down through the sugar; it mixes with the treacle 
that still adheres to the sugar, and by rendering it less 
viscid hastens its descent to the bottom of the form. The 
mud does not mix with the sugar, but after the water has 
drained out it remains on the top in the form of a hard, dry 
cake, which is very easily removed. 

For the purpose of refining the sugar after it has been 
obtained, refineries are built; these buildings are eight or 
nine stories high. The raw sugar is first hoisted to the top 
story, where it is dissolved in large tanks of hot water, great 
care being taken to use as little water as possible for the 
purpose. A quantity of bullock’s blood is stirred into the 
solution of sugar, and heat applied. As the heat is gradu¬ 
ally raised, the albumen of the blood coagulates and rises 
to the surface in the form of a thick, light scum and bring¬ 
ing with it nearly all of the mechanical impurities contained 
in the fluid. 

When all the impurities have been removed the liquid, 
while still hot, is emptied into filters made of very closely- 
woven cotton cloth, which retains even the most minute 
particles of mechanical impurity. 

When the liquid passes from these bag-filters it is free 


THE TEACHER’S AID , 


291 


from all impurities, but is of a dark color. It is next run 
into an iron filter, which is cylindrical in shape and from six 
to eight feet in diameter and twenty or thirty feet in height. 

This large filter is filled with animal charcoal, which is 
reduced to a coarse powder. The discolored liquid is 
allowed to run very slowly through this mass of charcoal, 
and the result is that it runs out at the bottom a perfectly 
transparent and pure solution of sugar. 

The charcoal can only be used for a few days at a time, 
because in collecting the impurities from the liquid it 
becomes impure itself and loses its purifying powers, and 
when the liquid begins to flow through it without being 
purified it is taken out of the filter and re-burned, which 
renders it perfectly pure again. This process enables the 
charcoal to be used repeatedly. 

When the liquid has passed through the charcoal filter 
it is a mixture of pure sugar and pure water in the form of 
a syrup which is perfectly transparent; the water is removed 
by the application of heat, and only the pure sugar remains. 

When thus purified, the sugar takes the names of lump, 
loaf, pulverized, refined, etc., according to the different 
degrees of purification it has undergone, and in these forms 
it is ready for the market as the sugar of commerce, and for 
this purpose it is usually packed in wooden barrels. 

Maple sugar is the product of the juice of the maple tree. 
In the manufacture of this sugar the juice or sap of the tree 
is obtained by tapping the tree. This is usually done in the 
spring of the year, when the sap is up or rising. 

The tapping consists in boring holes in the trees, usually 
only a foot or two from the ground; in these holes are 
inserted small curved or hollow pieces of wood, which con¬ 
vey the sap, as it rises, to buckets, tubs or troughs which 
are placed at the foot of the trees to receive it. 

As these vessels are filled they are emptied into larger 


292 


THE TEACHER'S AID. 


vessels and conveyed to the sugar-camp, and when a suf¬ 
ficient quantity of sap has been collected it is put into large 
iron boilers, under which fires are kindled. 

After this the process of reducing the sap to sugar is very 
similar to the one employed in the making of cane-sugar 
and beet-root sugar. It is boiled, clarified and skimmed, 
and when sufficiently granulated it is allowed to partially 
cool and is then poured into moulds of different sizes and 
shapes and allowed to become perfectly cold. When cold 
it is quite hard and is of a brown or j^ellowish-brown color 
and in this form and shape it is ready for the market. 

Sugar is an approximate element of the vegetable king¬ 
dom and is found in some proportion in most ripe fruits 
and in many farinaceous roots. It is converted into alco¬ 
hol by means of fermentation, and for this reason it forms 
the basis of the substances which are used in making intox¬ 
icating liquors. Of all the principles of the vegetable 
kingdom, it is considered the most wholesome and nutri¬ 
tious. 

The price of sugar varies according to the kind and 
quality; the production and demand also helps to regulate 
the price. The different kinds of sugar vary in color from 
the pure white to the yellow and the very dark browns. 
It is a useful and almost indispensable article, and large 
quantities are consumed annually. Its manufacture gives 
employment to many people. 

Remarks on cost, uses, manufacture, etc., of sugar. 

^ 

SARCOPHAGUS. 

Sarcophagus is a species of stone; it possesses the prop¬ 
erty of consuming the flesh of any body placed within a 
receptacle made of this material. This process requires 


THE TEACHER’S AID. 


293 


only a few weeks, and the entire animal substance, with the 
exception of the teeth, is consumed. Sarcophagus, accord¬ 
ing to the general acceptation of the term, means any stone 
receptacle for a dead body. Sarcophagus means flesh¬ 
eating; hence the name. 

On account of its flesh-consuming properties it was used 
by the ancients for making coffins and tombs, and the use 
of stone receptacles for the interment of persons of distinc¬ 
tion and title has not been entirely discontinued. 

The oldest sarcophagi are those of Egypt, some of which 
date as far back as the pyramids. The earliest of these 
stone receptacles were formed in a square or oblong shape 
and were either plain or ornamented with decorations of 
lotus leaves. The oblong sarcophagi are of the form of 
swathed mummies and are ornamented with inscriptions. 
The Roman sarcophagi of the very early periods were made 
plain. 

It is a very ordinary-looking stone, but does not occur 
abundantly in nature, and owing to its very peculiar prop¬ 
erty, receptacles made of this material are quite expensive, 
and for this reason it is a rare, rather than a common, recep¬ 
tacle for the dead. 

Note: Remarks on uses, properties, etc., of sarcophagus. 

YEAST. 

Yeast is a substance obtained by the fermentation of 
saccharine fluids. It possesses the power of setting up fer¬ 
mentation in fluids, and in dough for bread, cakes, etc., it 
causes a fermentation, owing to the same causes, which 
makes the dough light and puffy. 

In fermentation the ordinary clear fluid becomes turbid, 
and carbonic acid is evolved, and the substance causing the 


294 


THE TEACHER'S AID. 


turbidity gradually separates in a grayish, foamy mass of 
a bitter taste and acid reaction. This is known as yeast. 

Investigations have shown that there are two varieties 
of yeast—surface yeast, which collects on the surface of the 
fermenting fluid, and sediment yeast, which forms a sedi¬ 
ment at the bottom. In their chemical relations the two 
kinds present no apparent difference. 

If surface yeast be collected and placed on a cloth to 
drain and then pressed until almost dry, it can, without 
care, be kept for several months and in that state is known 
as German yeast and is used almost exclusively by bakers. 

Patent yeast is similar, but is raised from wort, made 
purposely from malt and hops. 

Artificial yeast is a dough made from meal and flour, 
mixed with a small quantity of common yeast and made 
into small cakes, which are dried. If kept free from moist¬ 
ure it retains its fermentive power for a long time. 

Remarks on cost, uses, etc., of yeast. 

FEATHERBONE. 

Featherbone is the name applied to the midribs of 
feathers when they are subjected to an operation by which 
they are converted into a material which forms a substitute 
for whalebone. 

In the manufacture of featherbone the midribs of the 
feathers are separated from the fibres and are split length¬ 
wise in fine pieces. The pieces are then fastened together 
in long strips by the use of glue and strong cotton or linen 
thread; the glue is mixed with the bone fibre and the thread 
pressed into it, giving it the appearance of being woven. 

The strips of featherbone, when completed, are of dif¬ 
ferent sizes according to the uses to which they are to be 


THE TEACHER'S AID. 


295 


applied, the usual size being intended to take the place of 
the ordinary whalebone. 

Featherbone is of a gray or yellowish-gray color; it is 
sometimes covered with pretty, bright-colored coverings, 
which are sewed in the form of a casing. 

It is a very flexible material and can be bent in any 
direction; and although quite hard, it can be sewed through 
either by hand or machine. It becomes much softer and 
more pliable upon the application of water and heat. 

The principal uses to which featherbone is applied are 
in the manufacture of corsets and as a stay for dress waists, 
skirt bindings or where a stiff, smooth effect is desired. 

The manufactured featherbone, when not encased in the 
cloth casing, is quite inexpensive; the price of the covered 
bone depends on the value of the material used in the 
covering. 

Featherbone is manufactured very extensively and has 
proven a very profitable industry. 

Remarks on cost, uses, manufacture, etc., of feather¬ 
bone. 

jt & 

RUSH. 

Rush is a genus of plant the species of which are very 
numerous; they are natives of wet, marshy places in the 
colder localities, although some are found in the tropical 
regions. 

Some kinds are absolutely without leaves; some have 
leafy stems, the leaves roundish or compressed. This kind 
is usually jointed internally. 

Some have plane or grooved leaves on the stems, while 
others have very narrow leaves rising from the root. 

Perhaps the name rush properly belongs to the species 


296 


THE TEACHER'S AID. 


which have no proper leaves, the round stems of which are 
used in the manufacture of mats, baskets, chairs, etc. 

The soft rush is cultivated in Japan for making mats 
and for other purposes. 

Rushes were used as coverings for floors in ancient times 
before carpets came into use. The stems of the true rushes 
contain a large soft pith, which is often used for candle 
wicks. 

Rush candles, or rush-lights, are made by removing the 
outer part from the pith, except a small portion to hold it 
together, and then dipping it into tallow. This makes a 
small, blinking and not very bright light. Rush-lights 
were much used in early times. 

Rushes are also used for making coarse ropes. 

Remarks on cost, uses, manufacture, etc., of rush. 

QUEENS WARE. 

Queensware is a glazed earthenware of a cream color. 
Some of the finest specimens of queensware in the world are 
manufactured at Sevres, France, and Dresden, Germany. 

The fragility and daintiness of queensware is its chief 
charm. Lovely tints and colorings are given to the queens¬ 
ware in its manufacture, and the most valued varieties are 
almost thin enough and clear enough to distinguish objects 
through them. It is manufactured in much the same way 
as porcelain, china and delft. 

Remarks on cost, uses and manufacture of queensware. 


THE TEACHER'S AID. 


297 


VARNISH. 

Varnish is a thick, semi-transparent, glossy liquid, con¬ 
sisting of a solution of the various resinous matters in alco¬ 
hol or oils. It is applied to the surface of wood, leather, 
metals, etc., for the purpose of finishing them. 

It must be made of a proper consistency to spread over 
the surface in a smooth coat or layer, and when dry becomes 
hard and shiny. But if not possessing the required gloss it 
can be polished mechanically or by hand. Varnishes are 
made from different materials and for different uses. 

There are two kinds of varnishes—the spirit-varnishes, 
made from the lacs and gum-mastics in spirits, and the 
oil-varnishes, made from the copals and anine in oils. 

In each case the materials used are reduced to var¬ 
nishes by means of heat in the form of hot water. This 
method of uniting the resins with the oils and alcohol is 
employed to avoid combustion. 

Great care must be taken in the manufacture of var¬ 
nishes, owing to the inflammability of the material used. 

Hence, a suitable factory and expert workmen are 
necessary. Coloring matter is frequently added to varnish, 
and black, amber, red, yellow and other colors are pro¬ 
duced. 

Note: Remarks on uses, cost, etc., of varnish. 

jt 

CORAL. 

Coral is a calcareous secretion, consisting chiefly of car¬ 
bonate of lime. It is the solid portions within the tissues 
of polyps and corresponds to the skeleton in the higher 
animals. 


298 


THE TEACHER'S AID. 


These pofyps, of which there are many different species, 
assume various and beautiful forms and colorings. 

The coral-producing zoophytes are compound animals 
and increase by gemmation. The surface is usually cov¬ 
ered with radiated cells, each of which marks the position 
of a polyp. Young polyp buds spring from the original 
polyp, from any part of the animal’s surface, or sometimes 
only from the upper edge or from the base, and remain 
attached in the same place even after the original polyp is 
dead. These young polyps produce buds in like manner 
and in this way a mass is formed. 

One layer is sometimes deposited upon another, while 
again they are very apt to grow* in circles around the 
original polyp, and in some instances they branch like 
shrubs, spread like fans, or take on the appearance of a 
flower, mushroom and various other forms. 

When alive, the animals appear like flowers over every 
part of the zoophyte. The whole living part soon decom¬ 
poses and disappears when removed from the water. In 
some species it runs out immediately in the form of a slimy 
substance. 

Coral is usually found in the seas of warm climates where 
they form reefs, banks and islands. Their bright and 
varied coloring gives them the appearance of a flower gar¬ 
den under water. These islands and reefs are often of a 
large size, some reefs extending in an unbroken line for 
miles. 

Coral islands are often covered with a beautiful and 
luxuriant growth of vegetation, owing to the accumulation 
of sand, decayed matter, etc., collected on their surface. 

The coral of commerce, or common red coral, is chiefly 
obtained from the Mediterranean sea, in some parts of 
which there are extensive coral fisheries. This coral is 


THE TEACHER'S AID. 


299 


noted for its beautiful color and the readiness with which 
it can be polished. 

Besides the red variety there is also the black coral, 
which is much scarcer and consequently more valuable. 

Coral was known and used by the ancients for orna¬ 
mental purposes. Ornamental purposes, and in jewelry, 
are its chief uses at the present time. 

Coral is procured by means of grappling-hooks, which 
are attached to boats. These hooks aro then dropped into 
the water, where they fasten onto the coral at a consider¬ 
able depth in the sea. They are then drawn up, and the 
coral mass is removed. 

This process is repeated until a boat-load is obtained. 

The live part or soft substance soon dies or runs out 
from the hard parts when removed from the water. 

And the hard part or skeleton of the animal forms what 
is known as the coral of commerce. All impurities are then 
removed, and after being thoroughly cleaned it is ready for 
the market. 

Note: Remarks on uses, cost, etc., of coral. 

jit jt & 

WAX. 

Wax is the name applied to various well-known sub¬ 
stances of a waxy appearance and nature. These sub¬ 
stances are obtained from the animal, vegetable and min¬ 
eral kingdoms. They are solid or semi-solid and are easily 
broken when cold, but at a moderate heat are soft and 
pliable and melt at a very low temperature. 

They have a peculiar, shiny appearance, are lighter than 
water and insoluble in it, but dissolve readily in ether, 
hot alcohol or any other heated liquid. They ignite readily 
and burn with a bright flame. 


300 


THE TEACHER’S AID. 


The most useful waxes are spermaceti, bees-wax, Chinese 
wax, palm or vegetable wax, sugar-cane wax and mineral 
wax. 

Bees-wax is an animal wax formed by the bees from 
sugar, and constitutes the material from which the honey¬ 
comb is made. It is obtained by fusing the comb in boiling 
water. When heated the wax rises to the top; it is then let 
cool and becomes a hard cake or crust on the top of the 
water, from which is it easily removed and the water 
drained off. The under side of the wax is often discolored 
from the impurities and is therefore scraped off and melted 
with the next lot to be worked up. 

The purified portion is then remelted and allowed to 
drop from the melting-pan into a wooden cylinder partly 
immersed in water and revolving rapidly in a large tank. 
This throws the wax into the water in the form of fine, thin 
flakes, which cool and harden immediately. 

The wax is then removed from the water, laid on linen 
cloths and placed on tables for the air to dry and bleach. 
These flakes are examined and turned occasionally, and 
when the bleaching effects of the air seem to have ceased 
they are re-meltecl and converted into flakes again, and 
spread out to bleach; this process is continued until the 
flakes are quite white. 

In the impure, unbleached state bees-wax is of a dirty 
yellow color. The commercial value of bees-wax is very 
great; it is used in the manufacture of candles, for medic¬ 
inal ointments, modeling and for making wax flowers and 
fruits. 

The wax for the making of flowers and fruits is bleached 
and prepared in sheets of various sizes and colors, which are 
cut into the shapes of leaves, petals, etc., according to the 
kind of flower or fruit to be made. These leaves and petals 


THE TEACHER’S AID. 


301 


are easily made to adhere by the application of a slight 
amount of heat or a little melted wax. 

Chinese wax, or insect wax, is the product of a very 
small, white insect. This insect is a native of China and is 
found about the beginning of June on the branches of cer¬ 
tain trees, on the juice of which it feeds. They deposit the 
wax on the branches in the form of a coating which resem¬ 
bles frost. About the last of August this wax is scraped 
off, melted in boiling water and strained through a cloth. 

Another wax insect inhabits South America, but very 
little is known of it. 

Vegetable wax is obtained from different kinds of palm 
trees—in some species from the seeds, in some from the 
leaves, and from the berries of others. This wax is used 
chiefly in the manufacture of candles. 

Mineral wax is a natural product found oozing in small 
quantities from rocks of a coal formation. It has become 
an important article in the manufacture of candles. When 
found, it has a dark, rich brown color, slightly greenish and 
translucent, but when refined resembles well-bleached 
bees-wax. 

Mineral wax has been found in Roumania, Wales, Scot¬ 
land, Utah and California. The manufactured compounds 
known as wax are sealing wax, moulder’s wax and gilder’s 
wax and are composed of bees-wax and other ingredients. 

Remarks on sealing wax, wax figures, wax dolls, cost of 
wax, etc. 

& £ 

CINNAMON. 

Cinnamon is the spicy, aromatic and stimulating bark 
of a certain species of the genus cinnamomum. Cinnamon 
has been in use from ancient times. The finest variety 
comes from the island of Ceylon. 


302 


THE TEACHER’S AID. 


The cinnamon tree attains the height of from twenty to 
thirty feet and is sometimes eighteen inches thick. Its 
bark is of a grayish-brown color on the outside, but inside 
of a yellowish-red. 

The leaves, which are from four to six inches long, have 
very blunt points and taste like clover. The flowers are of 
a silky gray color outside and a pale yellow color inter¬ 
nally. 

The fruit is a small drupe, of a brown color when ripe, 
and in shape very much resembles the acorn. There are 
two seasons of cinnamon harvest in Ceylon. The first, 
from which the best crop is derived, begins in April, and 
the last in November. The branches of from three to five 
years’ growth are cut down, the outer covering or skin is 
scraped away, and the bark is cut lengthwise with a sharp 
knife and gradually loosened until it can be taken off. 

The slices of bark are then exposed to the sun, and as 
they dry they curl up into quills. The finest cinnamon is 
yielded by the young branches of the tree, particularly 
from the numerous shoots that spring up from the stump 
after a tree has been cut down. These sprouts are cut 
when they are from ten to twelve feet long and about as 
thick as a common walking-cane. 

Cinnamon is examined and arranged according to its 
quality. The persons who do this are obliged to taste and 
chew the bark, which in a short time produces very dis¬ 
agreeable effects on the mouth and tongue. In packing, 
the smaller quills are packed inside the larger ones, and 
when arranged in this way are done up in bundles and are 
ready for the market. Cinnamon, like other spices, is used 
by cooks and confectioners and also in medicine. 

Note: Remarks on the uses, cost, manufacture, etc., 
of cinnamon. 


THE TEACHER'S AID. 


303 


EMERY. 

Emery is a variety of mineral stone. It is opaque and 
not crystallized. In color it is a grayish-black and some¬ 
times bluish. It is found both in masses and scattered, 
generally in masses scattered through aqueous deposits, 
but in some places in beds of steatite. 

Being hard, it is much used for grinding glass, polishing 
metal and other hard substances. Emery is composed of 
alumina, oxide of iron and silica, with a little lime varying 
in proportion with the different species. It is prepared for 
use by first breaking it into lumps about the size of a hen’s 
egg and then crushing these to a powder. 

It is then sifted to various degrees of fineness, which is 
regulated by the size of meshes of the sieve through which 
it passes. Emery, being next to the diamond and diamond 
dust in hardness, is used by the lapidary for cutting and 
polishing many kinds of stones. 

Glass-stoppers of all kinds are ground into their fittings 
with it. Plate-glass is ground fiat by its use. It is also 
used in glass-cutting and in grinding various kinds of fit¬ 
tings. 

When used for polishing metals it has to be spread on 
some kind of a surface to form a sort of fine file. For this 
purpose emery paper is made. It is made by sifting emery 
over paper that has been covered with a coating of glue. 
It is used wrapped round the hand or a fine file or stick, 
according to the form of the work. 

Emery cloth is made in the same way as emery paper, 
with coarse cloth substituted for the paper; it is more dur¬ 
able than the paper. Emery stick is made of deal sticks 
sharpened like files, covered with glue, and dipped once or 
twice into a heap of emery. 

Emery cake is a compound formed of bees-wax, suet 


304 


THE TEACHER'S AID. 


and emery melted and well worked together. It is applied 
to buffing-wheels, etc. Emery stone is a kind of earthen¬ 
ware mixed with emery and pressed into suitable moulds. 

It is moulded into wheels, etc., for grinding purposes, 
and its cutting power is very great. Emery will cut or 
wear any known substance except the diamond. 

Note: Remarks on the uses, cost, preparation, etc., of 
emery. 

jt ^% 

PAINTS. 

Paints, or pigments, are the names applied to the pre¬ 
pared or unprepared compositions with which wood, stone, 
iron-work, etc., are coated in order to give them a preserva¬ 
tive surface. A coating of paint also enhances the appear¬ 
ance of the surface to which it is applied and thus acts as a 
beautifier as well as a preservative. 

Paint consists of earthy matter, which forms the color 
and consistency and is mixed with oil. It is used by artists 
to produce the colored surface of their pictures. The paints 
now in use are nearly all mixed with a liquid and applied in 
a liquid state. 

The mixing materials are varied according to the nature 
of the work. Thus for some kinds of decorative work and 
for water-color drawings, gum, glue, size or other adhesive 
materials dissolved in water are employed. 

While for painting, etc., and for oil-paintings, oils of 
various kinds are used for mixing and thinning the colors, 
linseed oil, or turpentine, or linseed oil and turpentine 
together, being the chief oils used. 

Most of the paints used for ordinary purposes are com¬ 
posed, first, of the coloring matter, then a quantity of 
white-lead, which, with oil, are worked together into a 


THE TEACHER’S AID. 


305 


paste, and when used for painting and decorating it is 
thinned to the desired consistency with oil and turpentine. 

The principal part of most paints is composed of white- 
lead, which is the leading white paint used, as it does not 
readily discolor from impurities in the atmosphere. 

White-lead is obtained by subjecting pieces of lead to 
the action of the steam of acetic acid in beds of fermenting 
tan. White paints are also prepared from oxide of zinc. 

The different coloring matters in paints are numerous 
and are obtained from various sources in the animal, vege¬ 
table and mineral kingdoms and consist of a great variety 
of colors. 

A great many other than the original colors are formed 
by the mixture of the different coloring matters, and the 
effects thus produced are very useful and beautiful. 

In all cases the coloring materials for paints require to 
be finely ground, and as many of them are very poisonous, 
great care is required in the handling and preparation of 
them. 

Different forms of mills have been invented for the 
preparation of the various kinds of coloring materials. The 
chief objects of these mills are, first, to protect the oper¬ 
ators from breathing the poisonous dust, and, second, to 
reduce the coloring material, if ground dry, to an impalp¬ 
able powder, or, if ground with oil, to a perfectly smooth 
paste. 

Paint becomes discolored and spoiled, and its protective 
qualities impaired, if constantly exposed to light, heat or 
moisture. The addition of varnish to the mixed paints 
greatly improves their protective properties and renders 
them less liable to fade. 

The ready-mixed paints are done up in cans and sealed 

air-tight, and when slightly thinned with oil are ready for 

The water-colors are made up into hard, dry cakes 
20 


use. 


306 


THE TEACHER’S AID. 


without the use of oil and are used by dipping the brush in 
water and then on the cake of water-color to be used. 
Some grades of paints are very expensive, while others are 
cheap. 

Note: Remarks on the uses, cost, colors, etc., of paints. 

£ 

RICE. 

Rice is a genus of grasses, the only important species of 
which is the common rice. It is one of the most useful and 
most extensively cultivated of grains and supplies a large 
part of the food for mankind and is particularly adapted as 
a food for warm climates. 

The rice plant is an annual, varying in height from one 
to six feet. The flowers grow in panicles of one-flowered 
spikelets and two very small, pointed glumes. The florets 
are compressed, and the paleae, or chaff, strongly nerved, 
awned or awnless. 

The chaff, when the grain is ripe, is white, red, black or 
yellow according to the variety of the plant. The stems 
are smooth, and the leaves like those of grass, oats or 
barley. The seeds grow on small, separate stalks, which 
rise from the main stalk. 

Rice was originally a native of the East Indies, but is 
now in cultivation in most parts of the globe, particularly 
where there is warmth and moisture. It requires a moist 
soil and is adapted to tropical and semi-tropical countries. 

It is extensively cultivated in India, Japan, Egypt, in 
parts of Asia and in the southeastern part of the United 
States. 

There are a great many varieties of rice, and in India 
and Ceylon over one hundred are known. The best of all 


THE TEACHER'S AID. 


207 


known rice on the market is that from North and South 
Carolina. 

Rice is planted in different ways in different localities. 
In Carolina, rice is sown in rows in the bottom of trenches, 
which are about a foot and a half apart. These trenches 
are then flooded with water to the depth of two to four 
inches, and when the seeds germinate the water is drawn 
off. 

After the plants are several inches high the water is 
again turned on and permitted to remain about fifteen days 
in order to destroy any weeds that may have sprung up. 
It is flooded a third time, when the grain is almost ripe. 

In China the seeds are sown quite thickly on very wet 
ground, and when a few inches high it is transplanted in the 
fields where it is to be cultivated. 

The plants sprout or spread at the root, each plant send¬ 
ing up several shoots or stalks. Rice-fields should be kept 
free from weeds in order to prevent their seeds from mix¬ 
ing with the rice. 

This is a very difficult matter, as the ground is usually 
so soft and wet that in walking over it a man will sink quite 
deep and thus making it difficult to remove the weeds if 
they are permitted to get a start. 

In China and some other countries two crops are pro¬ 
duced in a year. In former times the gathering of the rice 
crop was difficult and tedious work. 

In the United States the present method is very similar 
to that of gathering the crop of wheat and other small grain. 
Before the grain is quite ripe the fields are flooded arti¬ 
ficially. 

But when almost ripe the water is let off, and the soft 
mud soon dries from the effects of the sun and heat. In 
this way a hard crust is formed on the surface of the soil. 

Machines are then taken into the field and the grain cut 


308 


THE TEACHER’S AID. 


% 


and taken care of in much the same manner as wheat. It 
is then threshed, cleaned and thoroughly dried. It is next 
done up in bags and is then ready for the market. 

The rice grain is a small, hard, flinty grain, of a white or 
whitish color; in size and shape it resembles the wheat 
grain, but is somewhat smaller and is round on all sides, 
while the wheat grain has one grooved side. 

Rice is particularly adapted as a food for warm coun¬ 
tries. It is very nutritious. Rice flour is made into bread 
in much the same manner as wheat flour is used. 

The Japanese make a beer from rice, and the Chinese 
make several kinds of rice-wine, which are extremely intox¬ 
icating. The well-known “arrack” of the eastern coun¬ 
tries is made from rice, and many of the distilleries of Great 
Britain use rice to a great extent in the manufacture of their 
beverages. 

Rice starch, also known as “patent starch,” is manu¬ 
factured in great quantities from the broken and refuse 
grains that are unfit for market. This starch is used in the 
manufacture of muslins, prints, etc., and in laundries. 

The rice straw is also utilized, being made into millinery 
and other straw goods. 

The cost of rice varies according to the grade, the variety 
and the yield. 

Note: Remarks on use, value, appearance, cost, etc., 
of rice. 

BENZOIN. 

Benzoin, or gum Benjamin, is a concrete, resinous juice 
or sap obtained from the styrax benzoin, a tree which is a 
native of Sumatra, Borneo and islands of the Indian archi- 


THE TEACHER'S AID. 


309 


pelago. When heated or partly decomposed it yields ben¬ 
zoic acid. 

This tree attains considerable size and is propagated 
from the small brown nut which it produces. Although a 
wild tree, it is also extensively cultivated for the benzoin 
which it yields. 

This tree attains considerable height and reaches nearly 
two feet in diameter; the small branches are covered with 
a rusty, whitish down. The leaves are oblong, acuminate 
and entire and are white and downy on the under side; the 
flowers grow in compound racemes. 

When the tree attains its fourth year it begins to yield 
its best sap. The sap is obtained by making oblique or 
longitudinal incisions through the bark of the tree into the 
stems and branches. These incisions are usually made in 
the stem near the ground, and the sap flows freely. 

This liquid sap soon becomes hardened by exposure to 
the sun and air. The sap obtained during the first two 
years’ tapping is of a creamy or light saffron color, and is 
soft and fragrant; but that produced from later tappings, 
or when old and dry, is solid and brittle, sometimes of a 
yellowish-white and sometimes of a uniform brown color 
like resin. 

The benzoin of commerce comes to us in reddish-yellow 
transparent pieces. The color and quality of benzoin is 
said to depend greatly on the age of the tree; the product 
of the younger trees, which is whitish, is said to be the best. 
The price varies greatly according to the quality. 

After the second or third year’s tapping it produces an 
inferior grade of sap of a reddish color, which is much 
harder than the better grades. In the course of a few 
years the sap ceases to flow and the tree is cut down. A 
very inferior resin is obtained by scraping the inner surface 
of the bark of the stems and branches. 


310 


THE TEACHER’S AID. 


Benzoin contains about ten to fourteen per cent benzoic 
acid, and the remainder of it is resin. It has very little 
taste, but its smell, especially when heated or rubbed, is 
extremely fragrant and agreeable, and it yields a pleasant 
odor when burned. 

And on account of the latter property it is largely used 
as incense in the Roman Catholic and Greek Catholic 
churches. But its chief use is for perfumeries and cos¬ 
metics. Tincture of benzoin is used medicinally in chronic 
pulmonary affections. It is applied direct to wounds, or 
when the edges of the wound have been placed in proper 
position by the use of plaster or lint it is used as an external 
application. It is also one of the ingredients of court- 
plaster. 

The tincture is also used in the manufacture of cos¬ 
metics, washes and soaps. Benzoin is a stimulant and may 
be eaten when mixed with sugar or egg. 

It was at one time erroneously supposed that benzoin 
was the product of benzoin odoriferum, a tree which is a 
native of Virginia. This tree attains a height of from ten 
to twelve feet, and it still bears in America the name ben¬ 
zoin or Benjamin tree and is also called spice wood or fever 
bush. 

This tree has a highly aromatic bark, which is both 
stimulant and tonic; it is used in North America as a cure 
for intermittent fever. The berries, which are also aro¬ 
matic and stimulant, were used in the United States during 
the Revolution as a substitute for all-spice. An infusion 
made of the twigs acts as a vermifuge. 

Note: Remarks on cost, uses, preparation, etc., of 
benzoin. 


THE TEACHER'S AID. 


311 


HAY. 

Hay is the stems and leaves of grasses when cut, dried 
and preserved. It is used as food for horses, cattle and 
sheep. 

In the process of hay-making the hay is cut with a mow¬ 
ing machine; it is then raked into winnows and by the use 
of pitch-forks is next made into small heaps or shocks. 

It is allowed to remain in the shock for several days in 
order to become partially dry, when it is made into stacks 
or ricks. The length of time necessary for the curing of 
hay varies according to the weather, the kind of hay and 
the amount of hay yielded per acre. 

The grass should be cut while in bloom, or before the 
seeds ripen, at which time it contains the greatest amount 
of moisture and nutrition. When allowed to dry before 
being cut the stems become dry and hard, its nutritive 
qualities are impaired, as is also its market value. 

Repeated rains and delay in curing hay injures its color, 
and instead of it being bright and clean looking it becomes 
dark and discolored. When hay has been injured in this 
way a little common salt sprinkled over it when it is being 
stacked makes it much more palatable to the stock. If cut 
at the right time and properly cured and stacked, hay will 
keep for a long time. 

The market value of hay varies in different localities; it 
depends largely on the kind of grass from which it is 
obtained, the care which it receives in preparation, and upon 
the supply produced and the demand for it. 

Large quantities of hay are used annually for the feeding 
of stock. Hay is extensively raised in some localities, 
while in other places very little is produced. The amount 
produced depends largely on the nature of the soil, the 
elevation of the land, the climate and various other causes, 


312 


THE TEACHER'S AID. 


and for this reason must be shipped from the hay-raising 
districts to the other places. 

Hay, being a bulky substance, requires a vast amount 
of space, and the expense of shipping would be very great; 
however, to overcome this difficulty, the hay is compressed 
into bales by the use of the hay-press. 

These bales are solid and of an oblong shape, weighing 
from one hundred to several hundred pounds, and are held 
in place by the use of strong, fine wire. Owing to their 
shape, they are easily packed for hauling and shipping. In 
this way a ton of hay is made to occupy a much smaller 
space than when loose, and is much easier handled. The 
hay used in the large cities is obtained in the baled or 
pressed form. 

Note: Remarks on cost, uses, care, etc., of hay. 

CIDER. 

Cider is the expressed juice of apples, and is used as a 
beverage both before and after fermentation. 

In making cider, the apples are first ground in a mill or 
hopper, which is operated by hand, by horse-power or by 
machinery, according to the size of the mill and the 
quantity of apples to be used. 

The ground or crushed apples pass off through the bot¬ 
tom of the hopper into a cylindrical wooden vessel, made 
of staves, placed a small space apart. In the bottom of 
this vessel is usually placed a lining of coarse cloth or clean 
straw. 

When filled with ground apples it is removed from under 
the hopper, and a coarse cloth placed on top and covered 
with a wooden lid a trifle smaller than the vessel. Pressure 
is then brought to bear gradually on the top, which forces 


THE TEACHER’S AID. 


313 


the juice out at the bottom and through the spaces in the 
sides. This pressure is continued until all the juice flows 
out, and the skin, pulp and seeds remain. 

The juice flows into a tub or tank, placed to receive it. 
It is then strained into casks or barrels and stored in a cool 
place, and in this form it is known as cider. 

In a few days, owing to the amount of heat it receives, 
fermentation sets in. During fermentation the sugar con¬ 
tained in the cider becomes converted into alcohol, and as 
the amount of alcohol is from five per cent to nine per cent, 
it becomes an intoxicant when drank in large quantities. 
In the fermented state it is known as hard cider. 

Cider rapidly becomes sour, and many ways have been 
tried to preserve it in its sweet state. One very successful 
way is to boil it down one-half, strain it and put it away in 
barrels in a cool, dark place. 

Another way is to put a certain amount of sugar or 
molasses to each gallon of cider; a half-peck of wheat added 
to a barrel of fresh cider is said to preserve the sweetness 
and retard fermentation. Many other methods are used, 
which have proved more or less successful. 

Cider is extensively produced in North America, En¬ 
gland, Ireland and Northern France. In many places great 
numbers of acid or bitter apples, known as cider apples, are 
raised expressly for the manufacture of cider. 

Some cider, if diluted with water and permitted to stand 
makes excellent vinegar. Vinegar is also obtained from 
the crushed apple or pomace after the juice has been 
removed. 

To procure the vinegar, the pomace is put into a vat 
and covered with water and allowed to ferment. The 
water is then drained off and strained and put into kegs or 


314 


THE TEACHER’S AID. 


barrels and allowed to stand, and in a short time is converted 
into excellent vinegar. The process is often hastened by 
adding a small quantity of sugar or molasses. 

Note: Remarks on cost, uses, etc., of cider. 

j* j* 

STARCH. 

Starch is an organized substance which is found in oval 
or roundish grains in the cellular tissue of some plants. 

It is very widely diffused throughout the vegetable 
kingdom, and is especially abundant in the seeds of the 
cereals, in the seeds of leguminous plants such as peas and 
beans, in the tubers of the potato, in the root of the arrow- 
root and tapioca, in the pith of the sago palm, and in many 
other plants, roots and grains. 

The grains of starch obtained from the same kind of 
plant are usually of uniform size and shape; but the size 
varies in the different species of plants. 

The ordinary starch of commerce is obtained in the form 
of a white, glistening powder, or in masses which can be 
easily pulverized, and when pressed between the fingers it 
makes a crackling sound. 

It is heavier than water and insoluble in cold water, 
alcohol and ether. If, however, placed in water which has 
a temperature of one hundred degrees, its grains or par¬ 
ticles will swell from the absorption of the water, and the 
mass will become of a viscid, pasty consistency. 

Starch is usually obtained by a simple mechanical 
process, which separates it from the other ingredients with 
which it is associated, and in making this separation advan¬ 
tage is taken of its insolubility in cold water. The details 
of the modes of separation of starch from the other sub- 


THE TEACHER'S AID. 


315 


stances vary according to the source from which it is to be 
obtained. 

Potatoes contain about twenty per cent of starchy mat¬ 
ter, and for this reason large quantities of potato starch are 
manufactured. In order to extract the starch from these 
tubers, they are first carefully washed to remove all par¬ 
ticles of earth or dirt that may be adhering to them, and 
are then ground or grated by machinery 

The pulp thus obtained passes out from the grinding 
machine onto a sieve, where it is continuously washed by 
a gentle stream of cold water as long as the washings which 
pass off look milky. This milky appearance is due to the 
presence of the granules of starch which are held in suspen¬ 
sion. 

The milky liquid passes into a vat, in which the starchy 
matter is allowed to settle; the water is drawn off, and the 
starchy deposit is repeatedly washed till the water is no 
longer colored. 

The starch is then suspended in a small portion of water 
and run through a very fine sieve to keep back any particles 
of sand. It is again allowed to settle and is drained off 
into baskets which are lined with thick ticking, and when 
drained, or partially so, the mass is placed upon a porous 
platform or floor of half-baked clay or tiles and dried in a 
current of air which at first is of the natural temperature, 
but this is increased, and the drying is finished by the appli¬ 
cation of a moderate artificial heat. 

The above method of obtaining starch applies to all 
substances which do not contain gluten. But for glutinous 
substances a more complicated process is required. Wheat 
and rice contain gluten in large quantities; it is either 
removed by fermentation or by a weak alkaline solution, 
which dissolves the gluten, but does not affect the granules 
of starch. 


316 


THE TEACHER'S AID. 


From a commercial point of view there are two classes 
of starch. One class is used as a food, and the other is used 
for manufacturing purposes. The food starches are 
obtained from arrow-root, corn, etc., and are used in the 
preparation of puddings, desserts and the like. The other 
kind is made from wheat, rice and potatoes; these starches 
are used in the manufacture of textile fabrics that require 
stiffening, and for laundry purposes/ 

The starchy ingredients in articles of food form a very 
important part. Starch is also regarded as the starting 
point in the preparation of brandy and almost all other 
forms of spirits, and of beer and porter, and it enters largely 
into the great saccharine group which constitutes the lead¬ 
ing articles of food. 

As an article for domestic purposes, starch is largely 
used in the laundry, as well as in the manufacture of dex¬ 
trine and grape sugar. Wheat-starch is the only variety 
that is used medicinally, and in this line it is used chiefly 
in the form of mucilages. 

When the starches have been obtained, no matter from 
what source, they are freed from all impurities and now 
form a beautiful white mass either in the form of small 
lumps or blocks, known as lump-starch, or in a fine, smooth 
mass known as powdered starch. 

It is then packed in boxes of different sizes, which are 
labeled with the name or kind of the starch and with the 
name of the manufacturer, and directions for using. 

The manufacture of starch is extensively carried on, 
and although an article largely used as a food and for 
manufacturing purposes, it is quite inexpensive. 

Note: Remarks on cost, uses, manufacture, etc., of 
starch. 


THE TEACHER’S AID. 


317 


ARSENIC. 

Arsenic is the term applied to a well-known poisonous 
substance, but properly speaking it is a metal of a steel-gray 
color and a brilliant lustre. It is quite brittle. 

It readily forms alloys with other metals, and when 
combined with sulphur it forms the yellow and red sul- 
phurets of arsenic. It is seldom found free in nature, but 
combined with other metals it is found in abundance. 

When found in the native state combined with copper, 
it appears in yellow, brilliant masses of different sizes or in 
different shades, and often in the form of crystallized 
needles. 

Arsenic is also found as a mineralizer in cobalt, copper, 
iron, silver, gold and antimony ores. The metal is gen¬ 
erally prepared from arsenous acid and an admixture of its 
own weight of charcoal. The mixture is placed in a tightly 
covered vessel and subjected to heat; the metal is set free 
by the action of the charcoal, and, rising, is condensed in 
the top of the vessel, from wdiich it is collected. 

Metallic arsenic is very brittle and can easily be reduced 
to a powder by hammering or by being pounded in a mor¬ 
tar. When freshly cut or exposed it presents a bright 
steel-gray lustre, which readily becomes discolored by con¬ 
tact with the air. 

As a metal it is not considered poisonous, but when 
introduced into the animal system it is acted upon and 
partially dissolved by the animal juices, and in consequence 
displays poisonous qualities. When ignited in the open 
air it emits a peculiar bluish flame and a peculiar odor. 

One of the uses to which mineral arsenic is applied in the 
arts is in the manufacture of leaden shot of various sizes. 
The presence of the arsenic renders the lead much more 
brittle than it naturally is. 


318 


THE TEACHER'S AID. 


When combined with sulphur, arsenic forms two very 
important compounds, one of which is known as realgar, 
which is a red, transparent substance used in the manu¬ 
facture of the signal-light known as white Indian fire, the 
other compound being king’s yellow, which is an inexpen¬ 
sive yellow pigment used by painters. 

Arsenic acid, when combined with oxide of copper, 
makes a cheap pigment of a pretty green color, which is 
used by painters and artists. These colors are also used in 
the manufacture of paper-hangings for walls. It is gen¬ 
erally believed that rooms decorated with such paper are 
injurious to the health. 

In medicine arsenic has long been used as a drug. It is 
a poison, and if taken in large quantities is very injurious 
and even deadly in its effects; but if taken in very small 
doses it does not prove fatal. But if the small doses be 
continued for a long time, symptoms of arsenic poisoning 
appear. The quantity necessary to destroy life varies with 
different people and different conditions. 

No effective chemical antidote for arsenic has been dis¬ 
covered. In case of an over-dose or an accidental dose, the 
usual remedy is to empty the stomach by the use of a stom¬ 
ach pump and lime water; draughts of tepid water and 
sugar, chalk and water or lime-water should be taken. 
The use of all alkalies should be avoided, narcotics used, 
and tepid baths frequently taken, and if fatal and injurious 
effects would be avoided, farinaceous food and milk should 
be used. 

Note: Remarks on uses, effects, etc., of arsenic. 




THE TEACHER’S AID. 


319 


IVORY. 

Ivory is the name given to the teeth or tusks of animals ; 
but the name is now usually applied to the tusks of the 
elephant, walrus and a few other animals, that of the ele¬ 
phant being the most valuable, and it is to the elephant’s 
tusk we refer when we speak of ivory. 

The tusks of the elephant are hard, solid, fine-grained 
and of a whitish color. They vary in size, being often six 
or seven feet long and weighing from only a few ounces up 
to one hundred and seventy pounds. 

The value depends on the size, soundness and color of 
the teeth. The ivory of the African elephant is very white 
and solid, and therefore much valued by the manufac¬ 
turers. Some varieties become yellow by usage, while 
others retain their pure whiteness. Ivory can be dyed any 
color, as red, yellow, green, plue, black, purple, etc., by the 
use of various chemical compounds. 

It can also be made semi-transparent and flexible by the 
action of chemicals combined with heat and water. It 
will, however, become hard when dry or exposed to the air, 
but readily resumes its flexibility when plunged into hot 
water. 

Ivory has been an article of great commercial value in 
the eastern countries from very early times, and the ivory 
trade has always been a very important and profitable 
industry. 

Owing to its great beauty and durability, many costly, 
valuable and beautiful articles are made from ivory. The 
art of working in ivory is supposed to have originated in 
India. 

From the time when man first drew the rude outlines of 
an animal on a mammoth’s tusk, ivory has always been a 
favorite article for the artist to work upon. It was used 


320 


THE TEACHER'S AID. 


extensively by the Assyrians and Egyptians for making 
ornaments, while among the Greeks some of the master¬ 
pieces of sculpture were wrought in ivory. 

Fashion’s changes have made some difference in the use 
of ivory. It is not now used so much in ornaments or in 
the arts. In the manufacture of billiard balls, however, 
it is still much employed, as thousands of tusks are used 
annually for this alone. 

Ivory has always been highly prized by the people of 
India. It is made into ornamental ear-rings, knife han¬ 
dles, umbrella handles, buttons and many other useful and 
ornamental articles. 

Ivory-carving has made wonderful progress in Europe, 
and many beautiful and ornamental works of art are on 
exhibition. The demand for ivory is increasing, while the 
supply is decreasing, owing to the fact that the elephant is 
rapidly becoming extinct. 

Ivory is obtained from the African countries and from 
India. The ivory of fossil elephants is found in large quan¬ 
tities along the shores of the Arctic ocean and on the islands 
of New Siberia. 

Vegetable ivory is a substance obtained from a South 
African palm. The nuts of this palm grow as large as an 
egg, and wdien ripe the kernel, which is remarkably hard 
and white, resembles ivory, and for this reason it receives 
its name. The vegetable ivory so closely resembles ivory 
that competent judges are often in doubt as to which it is. 
Vegetable ivory has only recently come into general use. 

Remarks on uses, where obtained, value, etc., of ivory. 


THE TEACHER’S AID. 


321 


FEATHERS. 

Feather, or plume, is the name applied to the covering 
of birds and fowls. A feather is composed of a shaft or 
stem, which is round, strong and hollow at the lower part, 
and the upper part filled with pith. On each side of the 
shaft or mid-rib are the veins or soft parts of the feather; 
these are broad on one side and narrow on the other, and 
consist of thin fibres. 

The smaller and softer feathers cover the body of the 
bird and are called the plumage; the feathers of the wings, 
which are hard, coarse and strong, are used as a means of 
flight. The tail feathers are much coarser than the body 
feathers, or plumage, and not as coarse and strong as the 
feathers of the wings. The barbs or quills of the coarser 
feathers were used from very early times as writing pens. 

The chief uses to which feathers are applied are, first, as 
pens, owing to the peculiar elasticity of their barrels; sec¬ 
ond, as bed-feathers, due to the combined elasticity and 
softness, and, third, for ornamental purposes, due to their 
graceful forms and delicate tints and colors of the whole 
feather. 

For bed-feathers, goose-feathers are preferred, owing to 
their elasticity and durability ; the white has preference 
over the gray. The feathers known as poultry feathers, 
such as those of the turkey, chicken, guinea, etc., are less 
esteemed on account of their deficiency of elasticity. Wild 
duck feathers are soft and elastic, but they contain an oil 
which is very difficult to remove. 

The following is one of the several methods for preparing 
feathers for beds, pillows, etc.: A quantity of quicklime 
is mixed with clean water; the feathers are put in a tub and 
the lime-water is added to the depth of several inches. 

The feathers are allowed to steep in this for three or four 


21 



322 


THE TEACHER'S AID. 


days, being frequently stirred. They are then taken out 
and washed in clean w’ater until perfectly free from all 
impurities and then laid upon nets to dry. They are 
shaken occasionally while drying, and when thoroughly 
dry they are beaten to expel whatever dust they may still 
retain. 

Many large establishments prepare bed-feathers by 
steaming them, which is found to be a more profitable, 
economical and efficient process. 

When feathers are used for head-dresses or any other 
ornamental purpose, they are selected according to the 
forms and colors which they display. The ostrich feather, 
a very valuable kind, may be taken as an example of the 
way in which ornamental feathers in general are prepared 
by the plumassier. 

They are cleaned for using by being repeatedly washed 
in water; sometimes soap is employed, and sometimes only 
the clean water is used. When thoroughly cleaned they 
are next frequently subjected to a bleaching process by the 
use of burning sulphur. 

They are dried by being hung on cords, and when dry 
they pass into the hands of the dresser, who opens or sep¬ 
arates the fibres by shaking; he gives pliancy to the ribs by 
scraping them with pieces of glass, and he then curls the 
fibres by passing the edge of a dull knife over them. The 
stems are then wound round with fine tissue paper and 
fastened in place with very fine wire to give them a finished 
appearance. Several feathers are frequently bound to¬ 
gether in a bunch. 

If the feathers, whether of the ostrich or any other bird, 
are to remain in the natural color, very little more has to be 
done in the way of preparation; but if a change of tint or 
color is desired, this can easily be obtained, as the feathers 
readily absorb the dye-materials and can be made to assume 


THE TEACHER’S AID. 


323 


any tint or color desired. When dyed, except for black, 
the feathers generally undergo the bleaching process. 

The kinds of feathers chiefly used for ornamental pur¬ 
poses are those of the ostrich, adjutant, rhea, emu, osprey, 
heron, bird of paradise and many other birds with orna¬ 
mental plumage; also the feathers of some of the very plain 
birds and fowls are utilized for ornament after being col¬ 
ored, curled and dressed. 

The colored ostrich feather is used chiefly for millinery 
purposes, and the black for the same purpose and for High¬ 
land regiments and funeral decorations. The feathers of 
the white and gray marabout stork, which are exported 
from Calcutta, are remarkably soft and light, and are in 
great demand for millinery, muffs, boas, etc. The white 
kind sometimes sell for their weight in gold. 

The flossy kinds of rhea feathers are used for millinery 
plumes, and the long brown wing feathers for brushes and 
brooms. Osprey feathers are mostly used for military 
plumes by hussar troopers. Bird of paradise feathers are 
sought by Oriental rulers for turban-plumes, etc. 

Some feathers are quite expensive, while others cost but 
a trifle. The imported feathers always command a much 
higher price than the domestic ones. 

Note: Remarks on cost, uses, preparation, etc., of 
feathers. 

^i 

ALUMINIUM. 

Aluminium is one of the metals of which clay, granite 
and other rocky and earthy substances are composed; it is 
the characterizing ingredient of common clay, and is some¬ 
times called pure clay. When moistened with water it 
forms a plastic mass. 




324 


THE TEACHER'S AID. 


Sulphuret of alumina occurs in small, roundish masses. 
It is a hard metal of a snow-white or a yellowish color, 
somewhat resembling silver, but possessing a bluish hue 
more like zinc. 

It is very malleable and almost as ductile as iron; when 
subjected to heat in a furnace it fuses readily and can then 
be cast in moulds. When alumina is exposed to the air it 
does not oxide as much as zinc or lead. Neither is it 
affected by contact with cold water, and in most experi¬ 
ments that have been tried hot water does not sensibly 
affect it. 

When aluminium is melted it is a soft metal, with the 
appearance of pure silver, and having a density of 2.56; 
but when hammered or rolled its density is increased, and 
it becomes as hard as iron. It is a very light, sonorous 
metal; its weight is less than that of glass and about one- 
fourth that of silver. 

This metal has been recommended for the manufacture 
of bells, gongs, etc., as it gives forth a remarkably clear, 
sweet, ringing sound when struck. 

Aluminium and copper form several light alloys resem¬ 
bling silver, and also a yellow alloy very much like gold, 
but lighter in color. These alloys are used extensively for 
manufacturing purposes. 

Aluminium was first discovered in 1846, but it was many 
years later before this metal was brought into prominent 
notice and made use of for manufacturing purposes. 

In 1855 it was subjected to experiments by a French 
chemist, who succeeded in preparing it in large quantities 
in a compact form without much trouble; but the demand 
for the metal at that time was not great. 

In the manufacture of aluminium an aluminate of soda 
is first obtained by heating the mineral in combination 
with soda ash in a furnace; the aluminate is separated from 


THE TEACHER'S AID. 


325 


the soluble portions by lixivation, and when carbonic acid 
is added to this solution pure alumina is produced. 

This alumina is then formed into balls with common salt 
and charcoal, by being heated in an earthenware retort; in 
this operation chlorine gas passes through the retort and 
unites with the alumina, and the charcoal unites with the 
oxygen. The chlorine and the alumina sublime over with 
the salt and are collected in the form of a double chloride 
of alumina and sodium. 

This double chloride is heated in a reverberatory furnace, 
where, by the use of fluxes and metallic sodium, the metal 
is freed and falls to the bottom. It is then collected and 
cast into ingots, in which form it is known as aluminium 
and is now ready for use. 

After many years of experimenting a method has been 
discovered and is now in use by which aluminium can be 
produced at one-tenth of the former cost; this method has 
proved a financial and commercial success. 

In this method alum and pitch are calcined together, 
producing a cinder, which, after further processes, yields a 
compound which contains about ninety per cent of alumina. 
This method is much shorter than the one at first employed, 
the time required being only a week or two, where formerly 
six months were required. The yield of metal is also much 
greater by this process. Some of the products of this 
metal yield a yellow liquid which makes an excellent blue 
dye. 

Aluminium is used in the manufacture of ornamental 
articles, such as chains, jewelry, etc.; for small statuettes 
and works of art; for pencil-cases, opera-glasses, tubes, 
metal badges, medals, bells, gongs, buttons and many other 

useful and ornamental objects. 

The metal aluminium was first brought into prominence 
in France and England, and large quantities were at first 




326 


THE TEACHER'S AID. 


made from the alumina metal brought from Greenland. 

Note: Remarks on cost, uses, manufacture, etc., of 
aluminium. 

jt 

LIME. 

Lime is the oxide of the metal calcium and is known in 
chemistry as one of the alkaline earths. In a state of purity 
it is a white, caustic powder, with an alkaline reaction. 

It is obtained by heating pure carbonate of lime to full 
redness, and when the carbonic acid is expelled the lime is 
left. 

Commercial lime, which is obtained by burning common 
lime in a kiln, is usually very far from pure. This com¬ 
pound is known as quicklime , or, from the ordinary method 
of obtaining it, burned lime, in order to distinguish it from 
the hydrate of lime, or slack lime. 

Lime is used in the preparation of mortars and cements; 
for building and paving purposes, and it is also largely used 
as a fertilizer; in the purification of coal-gas; in the prepa¬ 
ration of hides for tanning; for various laboratory purposes 
and in many medical preparations. 

Lime is a grayish-white or yellowish-white substance, 
which, in the unslaked state, is very hard, resembling ugly 
rocks; but in the slaked state it becomes a fine powder. 

It is very injurious to the eyes and skin if allowed to 
come in contact with them, and for this reason great care 
must be taken both in preparing it for the market and in the 
use of it. 

Although it is a very necessary article for building and 
paving purposes, it is quite inexpensive. 

Note: Remarks on cost, uses, preparation, etc., of 
lime. Lime quarries of the United States. 


THE TEACHER'S AID. 


327 


LACE 

Lace is an ornamental fabric made of cotton, linen, silk 
or woolen thread; it is made either by hand, somewhat after 
the manner of making embroidery, or by machinery. 

The manufacture of lace by hand is an operation of 
exceeding nicety and requires both skill and patience of no 
ordinary kind, and the best productions of this fabric sur¬ 
pass all other applications of textile materials in costliness 
and beauty. 

Gold-lace and silver-lace, properly speaking, are laces 
woven either by hand or machinery and made of exceed¬ 
ingly fine threads of these metals, or from linen, silk or 
cotton threads which are coated with still finer threads of 
gold or silver. 

The making of lace has existed from very remote times. 
Some of the antique laces and some of the hand-made laces 
are exceedingly expensive. Machine-made laces, although 
often quite pretty, are not so expensive as the hand-made 
laces, because they do not require the skill or the length of 
time in production. 

Note: Remarks on the uses, cost, manufacture, etc., 
of lace. 

S & & 

INDIA RUBBER. 

India rubber, or, properly speaking, caoutchouc, also 
known as gum elastic and rubber, is an elastic substance 
obtained from the juice of a tree which is a native of South 
America, the West Indies, Mexico and Central America. 

The properties of India rubber must have been known 
in this country from very early times, because at the time 
of Columbus’ second voyage he found the natives of Hayti 




328 


THE TEACHER’S AID. 


making use, in their games of sport, of balls made of the gum 
of some tree; this is presumed to have been India rubber. 

The rubber tree grows to a height of from forty to forty- 
five feet, the branches forming only at the top in the shape 
of a huge umbrella and covering a space of from eight to 
ten feet. The leaves, which are of a bright green color, are 
oval and from six to ten inches long; they are thick, smooth 
and glossy on the top side. The bark of the tree is smooth 
and yellow. 

The fruit is in the form of nuts, which are very similar 
to the chestnut, but much smaller; the} r grow in three- 
celled capsules, which burst, when ripe, with a cracking 
sound resembling fire-crackers; the nuts, in falling, are 
thrown quite a distance. The rubber tree is very hardy 
and is not affected by either insects or animals. 

In the cultivation of the rubber plant the seeds, which 
are easily obtained, are planted in beds. When about a 
year old they are transplanted in nurseries in much the 
same way fruit trees are planted in this country. When 
two years old they are re-transplanted in their permanent 
places. 

At the end of the first year, after final transplanting, 
they will have attained a height of from eight to ten feet; 
they will increase about five feet the second season. The 
trees are placed about ten or twelve feet apart in the plan¬ 
tations. 

The soil most suitable for the cultivation of the rubber 
tree is a deep, rich loam, such as usually is found along the 
banks of rivers and streams in rubber-producing countries. 
It flourishes best in tropical climates and requires very 
little attention after it is a few years old. 

The juice, which produces the rubber, is of a milky 
appearance and is obtained by making incisions in the bark 
of the tree, from which the juice flows freely. There are 


THE TEACHER’S AID. 


329 


several methods employed for tapping, the most common 
of which is to cut a deep horizontal gash near the base of 
the tree, and from this gash a vertical one extending up the 
tree, other gashes are made in an oblique direction, the 
lower extremities of which connect with the vertical one; 
this mode of connection conveys the juice collected to the 
main gash at the base of the tree. In some cases the trees 
are cut down in order to obtain the juice; but this is a very 
poor method, and one very little employed at the present 
time, as the object is to make the yield as profitable as 
possible, which can only be done by preserving the life of 
the tree. 

The trees are first tapped when six years old, and the 
yield of juice per tree will average from one to three pounds 
of pure rubber. The yield will steadily increase for the 
ensuing five or six years. Tapping is done in the evening, 
the juice collected in the morning. 

The tapping is done in much the same manner employed 
in collecting turpentine. The tree is not in any way injured 
by the process, unless the gashes are made to penetrate the 
wood, and the yield seems to be practically inexhaustible. 

The trunk of the tree becomes scarred, bumpy and 
irregular from the effects of the repeated tappings; but the 
general health of the tree remains good, and it continues to 
yield juice in abundance for a period of from forty to fifty 
years. The tappings usually occur in May, and again in 
October, making two rubber crops each year. 

The juice is collected by placing small earthen vessels 
under the incisions made in the tree; when these are filled 
they are emptied into larger vessels, where the juice is per¬ 
mitted to stand. In a short time the watery portion 
evaporates, and the rubber solidifies. 

When a large quantity has been collected it is put in 
barrels supplied with faucets; the barrels are only partially 



330 


THE TEACHER'S AID. 


filled, and a quantity of water containing a solution of 
chloride, or sub-carbonate of sodium, is added. 

The contents of the barrels are frequently agitated, and 
at the end of twenty-four hours the water is drawn off, and 
the process repeated until the rubber separates and collects 
in a white mass. The rubber constitutes about forty-four 
per cent of the original amount of juice, and is what remains 
after the water and other matter has been removed by the 
above or any other process. 

Another method of obtaining the rubber from the juice 
is as follows: The juice, when it is collected from the small 
vessels at the trees, is emptied into larger ones of different 
sizes and shapes, where it is permitted to stand. Evapora¬ 
tion soon sets in, the water is expelled, and the rubber solid¬ 
ifies. In order to make the evaporation more complete, a 
gentle heat is applied by suspending the vessels containing 
the juice over a wood fire; this fire is kept up by the appli¬ 
cation of the fruit of the auricuri, and is so arranged that 
the smoke passes over and comes in contact with the con¬ 
tents of the vessel, and imparts to it that smoky, black 
color which the rubber of commerce usually possesses. 

When the water has evaporated, the rubber, while in the 
warm, liquid form, is poured into moulds of the desired 
shape and size, where it is allowed to cool and solidify. It 
becomes a tough,, solid, elastic substance, and in this form 
is known as the rubber of commerce, and as such it is 
shipped to the non-rubber producing countries. 

There is another method which is very advantageously 
employed to separate the rubber from the juice. This con¬ 
sists in mixing with the juice from five to six times its weight 
of water and then adding a certain quantity of common salt 
or hydrochloric acid, which causes the rubber to separate in 
the form of a white, opaque substance, which becomes 
transparent when dry. 


THE TEACHER’S AID. 


331 


The rubber is diffused throughout the juice in the form 
of minute globules, and not in solution, as is generally sup¬ 
posed. When the juice is permitted to stand for a short 
time, the globules rise to the surface in much the same man¬ 
ner in which cream raises on milk, and when exposed to the 
air it becomes dry, tough and very elastic; hence the name 
gum elastic. 

The name India rubber was applied to it when it was 
discovered that it possessed the qualities of rubbing out or 
erasing marks made by lead-pencils. It was used almost 
entirely for this purpose at first. 

It was not until after the year 1800 that it began to be 
applied to many of the uses for which it now seems indis¬ 
pensable. 

Pure rubber is composed of 87.5 parts carbon and 12.5 
parts hydrogen. It is often adulterated in order to cheapen 
it, but its qualities are always impaired by the process; it 
is also greatly injured by carelessness in handling while 
collecting and preparing the juice. 

Rubber is insoluble in water and alcohol, and is not 
affected by the action of acids or alkalies, except when the 
acids are concentrated and heat applied. 

It is soluble in naphtha, petroleum, chloriform, ether, 
bisulphide of carbon, turpentine, lavender and the essential 
oil of sassafras. Linseed oil and some others, when heated 
with rubber, cause it to soften and produce a thick, gluti¬ 
nous compound. 

At a moderate temperature rubber is tough, fibrous and 
highly elastic; but when subjected to a freezing tempera¬ 
ture it hardens and almost loses its elasticity, but does not 
become brittle. 

Pure rubber is now used only to a limited extent in the 
arts, but in the form of vulcanized rubber is employed for 
an endless variety of purposes. 


332 


THE TEACHER’S AID. 


The process of vulcanizing rubber was discovered by 
Charles Goodyear in 1843, and about the same time by 
Thomas Hancock, of England. 

In the operation of vulcanizing, the rubber is reduced 
to small particles either by being torn into shreds or crushed 
into thin pieces by the use of machinery, after which it is 
subjected to a thorough washing. 

Sulphur is the only necessary ingredient required in the 
vulcanizing of rubber, although other substances are added. 
The amount of sulphur varies according to the kind of rub¬ 
ber desired. 

For the vulcanized rubber, which is hard and horny in 
texture, the rubber is mixed with about one-third of its 
weight of sulphur and subjected to heat for several hours, 
the temperature being raised to about three hundred 
degrees Fahrenheit. For the soft kind about one-tenth as 
much sulphur as rubber is used, and less heat is required. 
The sulphur is generally used in the ground state, although 
some element containing sulphur, as bisulphide of carbon, 
may be used. 

Since the year 1843 the number of patents taken out for 
the application of rubber in various forms and for different 
purposes number over two thousand. It would be impos¬ 
sible here to enter into extensive details regarding the uses 
and applications of rubber, as they are too numerous and 
complicated. 

Rubber is used in the manufacture of rubber cloth for 
coats, hats, caps, overshoes, etc.; for surgical instruments, 
as bags, bottles and tubes; for machinery, as hose, belting, 
wheels, tires, washers, pipes, valves, and for many engineer¬ 
ing appliances; also in the manufacture of combs, pins, 
belts, buttons, knife handles, etc. It is used in many of the 
latter named articles as a substitute for ivory, jet, pearl, 
horn, coral and bone. It is much cheapen than some of 


THE TEACHER’S AID. 


333 


these materials, and, being susceptible of stamping, carv¬ 
ing, etc., many beautiful and ornamental designs are made 
from hard rubber. 

The chief rubber-producing countries are South America, 
Mexico, Central America, British India, Western Africa and 
the Indian archipelago. 

These countries annually export large quantities of rub¬ 
ber in the bulk form to the United States, France, England, 
Spain and other countries, where the manufacture of rubber 
goods forms a leading and profitable industry. 

Remarks on cost, uses and manufacture of rub¬ 
ber. Also on the cultivation of the rubber plant and rubber 
plantations. 



NOV 8 1001 










































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